Here are some beer can related links.  The placement of these links on my website does not indicate an endorsement of the sites.  Hopefully you'll find one or two useful or entertaining.

Rusty Bunch Chapter, BCCA 
BCCA (Brewery Collectibles Club of America) 
Canventory - Computerized system to catalog your collection 
Capitol City Chapter, BCCA 
Blue Gray Show - The World's Greatest Beer Can trading show! 
The Merry Bocksters Chapter, BCCA
DetectionNet - Information on Metal Detectors 

Friends and Fellow Collector's Sites, alphabetically ordered:

Baker, Dan: Beercansplus.com

Benbow, Mark: Rustycans.com

Gauger, Gary: Crowntainer Central

Gesland, Brent: Awesome Beer Can Finds

Karasek, Randy: Michigan Beer Cans
Menke, Matt: One Full Quart

Mobley, Bruce: Beer Bottle Library

Scoglietti, Dan: BeerCanMuseum.com