[supercat]

I don't know where these UXBs are, but cell phones don't work on the Underground

Even in the shallowest parts of the cut-and-cover lines, or the stations thereof (many of which are actually above grade)?

[pau1f0rd]

oh yes, two thirds of the tube network is actually above ground, but very little of that is in Central London. Once you get into the deep tunnels you're on your own :-)