Kitschy Roadside

Ohio Barns - http://www.ohiobarns.com
in addition to barns, contains info for all sorts of roadside attractions in the US

Retro Roadmap - http://retroroadmap.com
"vintage, retro and cool old places worth visiting"

Roadside America - http://www.roadsideamerica.com

Roadside Architecture - http://www.agilitynut.com/roadside.html

Roadside Peek - http://www.roadsidepeek.com
“ ... a roadside journey in time”

Space Age City - http://www.spaceagecity.com
includes a directory of googie architecture in the US
also listed under: linkorama/miscellaneous:everything else

World’s Largest Roadside Attractions - http://www.wlra.us