This might be considered a bit lower tech than my usual fair but is a lot more accessible for the general public. As an aside from a presence based mobile social network project he is working on with me and Will (I will blog about it in future) my MSc student Klen Copic Pucihar knocked up this very neat little WidSets Widget called Widget Maps that allows you to get your location position using an address search facility  which then plots it on Google maps on your phone. The widget also allows you then to move the cursor to your exact location and get the corresponding latitude and longitude which you can share with your friends. The nice thing is that this will work on any J2ME phone supporting WidSets client Irrespective of having access to some form of positioning technology (sort of low tech my location).

BTW its currently available as a beta widget on the Widsets site so enjoy