abcTeach - http://abcteach.com/ Great printables, ideas.

A to Z Kids Stuff - http://www.atozkidsstuff.com/presch.html Hard to search, but eventually you find good ideas. You have to search through categories like preschool, gr. 1, etc. or subject area.
http://www.atozteacherstuff.com/Themes/ Themes listing

Adrian Bruce's Links - http://www.adrianbruce.com/ Teaching 3/4's now

Activity Idea Place - http://123child.com/act/ Hundreds of ideas.

Alphabet Soup - http://www.alphabet-soup.net/theme.html Themes, but cluttered with advertising and annoying pop-ups.

Blue Web'n - http://www.kn.pacbell.com/wired/bluewebn/ Lots of links!

Bob's Place of Educational Links - http://www.bobsedulinks.com/early_teachers.htm Good listing

Busy Teacher's Cafe - http://www.busyteacherscafe.com/ Units, resources, learning packets.

CanTeach Elementary Resources - http://www.canteach.ca/elementary/ Poems, links

Connected Educators - http://www.castletechnology.com/resources/connectededucator.html Incredible list of links for teachers

Core Knowledge - Science - http://hometown.aol.com/mellettk/Webpage/CoreScience.html for Gr. 3

Danielle's Place - http://www.daniellesplace.com/html/crafts.html Craft ideas

Debbie's Unit Factory - http://www.themeunits.com/toc.html  She has topics with links to teacher materials and resources.

Discovery School: Kathy Schrock’s Guide for Educators - http://school.discovery.com/schrockguide/index.html  Tons of links

Early Childhood Educational Online Activities and Games - http://www.fastq.com/%7Ejbpratt/education/links/eceactonline.html Pratt's links - great! Themes: http://www.fastq.com/%7Ejbpratt/education/theme/themes.html

Elementary Education Resources - http://www.pitt.edu/~poole/kindergarten.html Great list of links

Enchanted Learning - http://www.enchantedlearning.com/Home.html This is so excellent, and you can download a lot of material for free, but you can also subscribe for $20/year.

ESC Teacher Resources - http://eteach.esc13.net/t_social.htm Great long lists of sites

Everything Preschool Themes - http://www.everythingpreschool.com/themes/ Organized alphabetically

Filamentality - http://www.kn.pacbell.com/kne_search.html A great site where you can search for any topic... you use the search engine & type in your topic plus "treasure hunt" or "subject sampler" and there are loads of already made webquests.

First-School Preschool Activities and Crafts - http://www.first-school.ws/ Simplistic themes, good for finding patterns; letter shapes.

Gander Academy Theme Pages: http://www.cdli.ca/CITE/themes.html 

Globe Teacher - http://www.globeteacher.com/ Ideas for lessons, units, teacher tools.

Hubbard's Cupboard - http://www.hubbardscupboard.org/index.html Michelle Hubbard has created this great resource. Themes: http://www.hubbardscupboard.org/themes.html

Hummingbird Educational - http://www.hummingbirded.com/ Peggy Drake has collected lots of links and theme ideas for early childhood.

Idea Box - http://www.theideabox.com/ideas.nsf/activity I love this site - the ideas are so excellent! The only problem is the difficulty in finding specific topics...

IDEAS - http://www.ideas.wisconsin.edu/index.cfm Prepped by the Wisconsin University and covers topics from Pre-K up.

ITeach 3 4 5's - http://hometown.aol.com/iteach345/page2/index.htm Thematic links

Jan Brett Activity Pages - http://www.janbrett.com/activities_pages.htm

Jenna's Website - http://hometown.aol.com/il2teach/pubpage.htm?f=fs Kindergarten themes

K-3 Homeschool Help - http://www.homeschoolingadventures.com/k3.html Lots of thematic units

K-Crew’s Units & Centers - http://www.thekcrew.net/units.html Ideas for centers

Kids Konnect - http://kidskonnect.com/AlphabetizedList.html Alphabetized list

Kindergarten Treehouse - http://www.kindergartentreehouse.com/Anderson.html Great ideas

KinderKorner - http://www.kinderkorner.com/index.html#units  Victoria Smith has a combination of free material as well as some can be purchased online

Lars Ekdahl's Kids Favorites - http://www.ekdahl.org/kideng.htm Variety of links

Laura Candler's File Cabinet - http://home.att.net/%7Eteaching/filecab.htm Limited, but good

Learning Pages - http://www.learningpage.com You have to subscribe to this site at no charge to access their material. Lots of printables, lesson plans, fact files that are theme based.

Lesson Planz.com -  Theme listing is on this page: http://lessonplanz.com/Lesson_Plans/Thematic_Units/

Lesson Plan Search - http://www.lessonplansearch.com/Thematic_Units/more4.html Like the search tool

Lesson Plans and Units - http://www.geocities.com/Athens/8854/lp.html Fairly generic

Little Giraffe's Themes - http://www.littlegiraffes.com/themes.html Good for preschool

Lori Weaver's Theme Sites - http://bcmnc.blount.k12.al.us/links.htm Focus on Special Needs within themes

Marcia's Lesson Links - http://www.marcias-lesson-links.com/ Long, long page with links; good resources, though, just hard to read.

Mrs. Fischer's Kindergarten Themes - http://www.kinderthemes.com/

Mrs. Mitchell's Virtual School - http://www.kathimitchell.com/ Excellent web collections - Note music background - loud!

Mrs. Pohlmeyer's Units and Themes - http://www.mrspohlmeyerskinderpage.com/unitsandthemes.htm This kindergarten teacher has spent a lot of time creating units and themes online.

Mrs. Silverman’s WebFolio - http://kids-learn.org/  Lots of online collaborative projects.

Needleman's Open Court - http://www.opencourtresources.com/ links to primary grades, units, printables

North Canton City Schools Elementary Theme Units and Online Activities - http://www.northcanton.sparcc.org/~greentown/grtheme.htm Excellent listing

North Carolina University - http://www.learnnc.org/lessons/ Searchable database

Perpetual Preschool Themes - http://www.perpetualpreschool.com/preschool_themes/topics.html  Hit and miss with topics

Prekindergarten Thematic Units - http://www.prekinders.com/themes.htm Great!

Preschool Rainbow - http://www.preschoolrainbow.org/alphabet.htm Lots of free ideas, but if you go to the "Resource Room" you will need to pay for these items.

Reading is Our Cup of Tea - http://home.att.net/~etonn/themes.html Themes based on literature

School Bell - http://theschoolbell.com/contents.html Kathy Gursky has created this wonderful site with themes, projects, and month-by-month break-down. Themes: http://www.theschoolbell.com/Links/themes/Theme_Index2.html#JKL

Science Resources - http://members.tripod.com/~ehlavaty/scires1.htm Gotta love this topic!

Teacher Pages - http://users.stargate.net/~cokids/teacher2.html excellent links

St. Mary's School, Fort Vermilion Links - http://www.fvsd.ab.ca/stm/Default.htm Cathy-Dee Brand has amassed a great collection of links

Surfaquarium - http://surfaquarium.com/NEWSLETTER/ Listing of links

Teach the Children Well - http://www.teachthechildrenwell.com/index.html Elaine Doolittle has collected a great resource of links.

Teacher's Corner - http://www.theteacherscorner.net/ Lots of ideas!

Teaching Heart - http://www.teachingheart.net/  Colleen Gallagher has created this site with awesome resources; she has created materials that you can purchase, but lots are free. http://www.teachingheart.net/units.html

Teaching Ideas for Primary Teachers - http://www.teachingideas.co.uk/sitemap.htm a U.K. site that is hard to navigate; good ideas and links though.

Teaching Treasures - http://teachingtreasures.com.au/ Australian site with pdf files, various topics

Thematic Units - Teachers Room - http://www.theteachersroom.com/thematic_units.htm kindergarten

Themes - http://www.geocities.com/i_love_teaching_prek/themes.html preschool ideas

Virtual Vine - http://www.thevirtualvine.com/themes&units.html I love this site!

Worthwhile Web Sites - http://kingedward.epsb.ca/wwl/ Sandra Gluth's site

Zwolle Elementary - http://www.sabine.k12.la.us/zes/resource/default.htm themes

Learning Activities - http://www.meddybemps.com/7.33.html

Ellen Closs - http://www.geocities.com/learningcenters2003/

Michigan Studies Teacher Resources - http://www.geocities.com/michstudies/

Preschool by Stormie - http://www.preschoolbystormie.com/themes.htm 

E-Themes - http://www.emints.org/ethemes/resources/by-title.shtml

Themes and Units - http://awalley2001.com/ThemesandUnits/themesandunits.html

Time Warp Trio - http://www.timewarptrio.com/teachers-parents/lessons/

Instructor Web - http://www.instructorweb.com

Teacher Helper - http://teacherhelpers.homestead.com/