I would look at getting a real gps unit like the 705, still a good solid unit but since it has been replaced recently there are some deals on them. This is a little bigger unit but has full gps capabilities and not just a bike specific computer. Ebay selling new units for 339.00, I've seen some for a little less..
http://cgi.ebay.com/New-Garmin-Edge-...item45f751f27a