If you're looking for a bluetooth GPS receiver, I purchased mine from
buy GPS Now - Navigation Products for Pocket PC PDA, PDA Phone, Bluetooth GPS, PDA GPS and received it within a few days... most any bluetooth receiver will work, I currently have two different units paired with my phone for my truck and my girlfriend's car. My favorite app to use with them is Google Maps, and it works flawlessly. Hell, it's better than an iPhone.
Me: "Oh, new iPhone huh?"
Friend: "Yeah, check this out!" (Demonstrates his Maps app)
Me: "Yeah, I got that too." (Demonstration of same app)
Friend: "Oh."
Me: "Yeah, and I paid about $350 less for this phone."