Are you using a PC with a Wi-Fi connection? Want to find out where you are? Try Loki, a fascinating geolocation browser plugin powered by Skyhook Wireless. This company (which I first heard about via Clive Akass's article for The Inquirer) has created a database of the physical locations of wireless access point MAC addresses that can help pinpoint your position surprisingly accurately - here in the wilds of Surrey it is only about 150m out. You can add a similar service that identifies the location of visitors to your website using the free Loki Javascipt API.
Skyhook also sells a cheap (£3) application for S60 phones called Maps Booster that augments the built-in GPS. It works very well - I bought it for my Nokia N86 and it gives an almost instant (albeit coarse) fix even if you turn off all the GPS and other positioning options. Very useful in built-up areas, too.