I'm using mapopolis on my 5555 and am planing on getting the blue logger. I have all of the state of Washington, Oregon, and Idaho on my storage card, with only half the space used on the 256mb SD card. You should be able to us the blue logger with other mapping software.
By the way, you can use one of these to get your pda sound to play to your car stereo. http://cgi.ebay.com/ws/eBayISAPI.dll?ViewI...5740995803&rd=1