Whats a good GPS to use for a speedo?

[Askotto@aol.com]

Other than an aircraft air speed indicator, what's the hot setup for  GPS'?
 
I narrowed my rear track today by 8". I'm sucking my wheels up to the body  
as they were hanging out in the breeze before. 
 
I also lengthened and tapered the tail 30.34" and added a vertical fin. Now  
my CG/CP ratio is much, much better. The CP is actually behind the CG by 
almost  a foot.
 
Odd Toe