Delorme has been making very small GPS receivers with serial output
for use with their laptop software for many years, back into the 90's
in any case. The first one I purchase was about the size of a deck of
cards and was $200 or so without the software - and it was considered
cheap and small. Now the receiver is the size of a book of matches
and go for $50 with the software.
http://shop.delorme.com/OA_HTML/DELi...&section=10091.

It was great for having a really nice moving map display on business
trips before the advent of all the automotive Garmin/Tom-Tom/etc
GPSs. Their software had a cool "radar" function that kept updating
you on the location of the nearest gas station (restraurant, hotel,
etc) along you travel path. All I needed was that small receiver and
my laptop (which I had anyway). And you can't beat a 15" display for
visibility!

They must have been really adversely impacted by the consumer GPS
revolution. I wish them well.

- John DeRosa