Sony Ericsson HGE-100

Simple to use, excellent concept, good sound quality, Tracker application an ideal fitness companion

Only works with certain Sony Ericsson phones, Wayfinder requires a fee for full use, user experience isn't the best on a small display

If you want a fully fledged GPS navigator, you are best off purchasing either a portable in-car unit or a handheld device with a larger screen. If you want to track your fitness data, then the HGE-100 may be worth a look.