Greg, Funny you asked that

I JUST read this a couple days ago and knew where to go find it again. I found it TOO late unfortunately, as I purchased the bundle again at WorstBuy for $99. I am just gonna sell the unopened software on eBay I think.
If you go to the VERY bottom of
THIS PAGE you will see the following:
"NOTE: If you already own a recent or current version of DeLorme mapping software and want to use any of them with the Earthmate GPS LT-20, you can purchase the receiver by itself. Call 1-800-561-5105."
This is on Delorme's site, where they are offering the Street Atlas USA 2006 Software/GPS bundle.
I have this exact GPS, and aside from the hideous color (at least when used in a CarPC enviorment) it works fantastic! It gets a lock very fast, and in Florida I usually have around 10-12 sattelites locked out of 12.
ONE MORE OPTION...
is to get a USB/PS2 adapter. URL=http://www.pricegrabber.com/user_sales_getprod.php?masterid=705058&lot_id=1791178&mode=googlegfr]HERE IS ONE[/URL] for $15. I did not do any price shopping, just the first one that showed up through Google. I know it will work with Keyboards/mice, but no idea if they will work with a GPS receiver or not... Hmmmmm