I have two MDA's - just got them about a month ago - love it.
I just got in the mail a Holux GPSlim 236 bluetooth GPS receiver. Works great.
Here is where I bought it...
http://www.pricegrabber.com/user_sales_get...;lot_id=3050387
$89
Tracks very fast even in my house. Needless to say I put it in my glove box and it still works. Long lasting rechargable battery. Real slick thing is the power connector is the same USB connector that the MDA uses - it's all swappable
So get a 12v car charger (works with the MDA as well) and a USB cable and a 120v to USB adapter to charge off the AC.
TheShaz