Mobile networks: the state's new bloodhounds?

http://www.theregister.co.uk/2007/11/04/location_information/

A pre-paid SIM, paid for in cash, should be standard-issue for anyone planning a crime spree, though few criminals have the foresight for such an investment, and forwarding your old number to it would be something of a giveaway.

Turning off your mobile, and removing the battery for the properly paranoid, should be good enough to ensure you're not being tracked.

If it's already too late, your only hope is that your crime doesn't warrant enough budget to track you down, or that no one notices it for the 12 months the network operators are hanging onto their data.