Depends on where you are and which carrier has the most towers and best signal. With respect to true GPS units, you might check out GPS forums because there are hacks for less expensive Windows CE based GPS units. I have a Mio C320 on which I have installed Mio Pocket. That gets me a true GPS unit capable of playing multi-media files, using CE-based office apps, using other GPS applications like Ozi Explorer CE (best off road GPS app for CE devices) and, using my Ambeon SD WIFI card, the Internet (Opera, Internet Explorer, Skyfire). I always have my GPS unit with me when I ride because I'm riding unimproved forest roads. The best data on them is from the USGS topo maps, which you are still able to download for free. I imported the topo maps for the forest I live in into Ozi Explorer so I don't get disoriented. Believe me, when all you see is thick forest canopy and you've traveled for a while deep into the forest, it starts looking the same and you can lose your bearings. With true GPS, I just need to find a clearing where the unit can get satellite signals, which is good because there aren't many cell towers here so phone-based GPS would be of no help.