I was writing enthusiastically some time back about pedestrian navigation services. Vodafone has included Mapway into the Vodafone live! service. So did O2 some days back.

It makes use of the location information from the phone network, which is inaccurate to locate the starting point, But it's better than nothing. It does however not track, if you are on the right way, since no GPS is normally available in the cell. Good work, considering just one round of investment of USD 1.7 mio.
Thanks Martina!