Yes, for example, all the Neo900 can do is to guarantee that turning off the
modem will actually do that. For a high price.
Unfortunately, for work, it's rather difficult to live without one. At best,
one can use Airplane mode on Galaxy S2 (supposedly, no signal goes out after
a reboot), or remove the battery when not at work. Actually I'll start trying
to use it that way (maybe attempt to write a script which switches that based
on the current time).
The next best choice is a Replicant-supported phone, because the tracking is
left "only" to the modem, not to other services (Goolge).
