Links
US
http://www.japanesenostalgiccar.com - One of the best sites dedicated to vintage Japanese cars. The 2 brothers that run this site are great guys to know as well.
Katy's Nest - US site dedicated to both a Japanese and American audience. These great people also organize the now famous Japaneseclassiccarshow.com held annually
Han Auto Performance - Electrical needs including engine/stereo and high performance: http://www.autohanperformance.com/
Dime Quarterly - Popular US 510 site: http://www.dimequarterly.tierranet.com/
SR20store.com - your SR source in the US: www.sr20store.com
Datsun History - comprehensive site on the history of Datsun cars including the 510 & Bluebird: http://www.datsunhistory.com/
Datsunlandsocal - Local Datsun parts vendor specilizing in hard to find parts: www.datsunlandsocal.com
http://www.hubcapnation.com
Japan
510 Jungle - Japanese website for a 510 club
Nissan Corporate Museum - Nissan Motor Limited corporate site
Super Sonic Line - nice Japanese site with very clean Bluebirds: http://member.nifty.ne.jp/datsun510