Just got a Motorola Droid 2 from Verizon that has a built in Satellite based gps. I used it recently to go on about a 45 mile ride down to Sarasota FL and was able to use my helmet speakers to hear the voice prompts clearly and it was accurate down to my destination. The thing I found pretty cool was that since it uses a google based operating system was that it pulled up a photograph from google earth to show my destination at the end. The available free applications for up to date weather and radar are a nice addition as well. I found a nice mount for it that I intend to purchase as well that will keep it out of the elements. http://www.amazon.com/dp/B003VKZRQI/ref=asc_df_B003VKZRQI1395150?smid=A2QDQQXLQ5UXT6&tag=shopzilla_mp_1303-20&linkCode=asn&creative=395105&creativeASIN=B003VKZRQI