There is small aplication for 7650 - minigps. Its not complete GPS (of course 😉 ) but it use cell info to localize phone. Good thing is that You can put descriptions to that info and it will show You your info, so if you are going to common places often it will show you info and - and this is best part - can change various settings of phone itself.
IE, If You are in the opera it will change profile into silent !
:P
REad more and download it here:
http://www.psiloc.com/nokia/eng/minigpsS60/index.html