Google Latitude Application
Have you heard about the Google Latitude application? I think this is a pretty cool way of staying in contact with people and it can certainly be used to increase your likelihood of bumping into one of your friends, or not bumping into them if you would prefer it that way!
You can use it on whatever mobile device you currently use. It works with lots of different models, for example, iPhone, Blackberry, Android, Nokia and so on. In essence, it is a piece of phone tracker software that you simply install onto your handset. This then lets you share your location with your friends, or not. You still have full control over your privacy settings so if you want to go off the radar, you still can.