Okay. I just noticed that someone did away with our useful sites thread that was stickied in this area. So... here it comes again.
The rules:
If you respond in this thread, your post must contain a site. This is not a thread to chat about anything, it is meant to be a useful tool for people to find stuff.
Read through all posts before posting. DO NOT post a site if someone already has.
Along with the site, in www.site.com format, post what they help with.
I'll start.
www.hmotorsonline.com - one of the best online JDM and domestic honda motor dealers I've ever found.
www.hasport.com - one stop shopping for swap kits, axles, mounts, adapter harnesses, etc.
www.rywire.com - the best in the biz for wiring harness conversion when doing a swap. these guys know their shit.