Easy.
- Download the My World GPS Tracker from LocationOf.com
- During installation on your phone, register an account
- Surf to your newly created profile at the website
Something like: http://www.locationof.com/your-username-here/ - Send the link to friends, so they can watch your whereabouts in real time!
There's a demo on the Mobile GPS Tracking Homepage, the app is free and supports almost any Nokia device with internal GPS.