R/C Crawling Forums/Websites:

RCCRAWLER - The best source for up to date crawling info, product reviews and more.

CLODTALK - A fantastic R/C forum with a great crawling section, especially for Clodbuster-based crawlers.

RCJIMSPLACE - Another great forum site with many unique categories, such as "Tamiya XC/Cross Country" and "Fabricators Area."

Scale 4x4 R/C Forum - Dedicated to "Scale" (realistic-looking) R/C 4x4's of many types. Always incredible projects to oogle.

RCMT: A large forum for all things truck, not just crawlers. They ahve a good crawling section as well.

Other R/C Crawling Clubs:

PARC (Phoenix Arizona Rock Crawlers)

UTRCRC (Utah R/C Rock Crawlers)

Nor-CalRCRC (Northern California RC Rock Crawlers)

SERCRC (South East Remote Control Rock Crawlers)

Find your club here!

Other Shiny Crawler-related Sites:

Bolt Depot: Get that 3mm bulk hardware at good prices!

Modelltruck.net: The German Trial Forum!

Truckmodellsport: German Trial Truck Parts

Mini-z Racer: Like little Crawlers? There are some neat trucks in here!

E-Machine shop.com: Online Machining

Plastruct.com: Browse their plastic stock. Build that Unimog 404 RC cab you've always wanted.

Garden trucking: Lots of info and products relating to scale rigs!

Robbe Modellsport: Some neat accessories and components, as well as vehicles.

How to work with tubing, by ROKTOY: A great writeup on RCcrawler about making tubers.

Tinyrc.com: More about little crawlers.