In preparation for an upcoming trip, we picked up a set of three LG ME 770 phones, these are the same as the LG HE 770 only are American centric with the 1800 band for overseas travel, which means we should be hot to trot for the UK.

But we still need SIMs. The phone won't do anything until I put a SIM in, to include access to all the MP3 playing capabilities and the camera which we want to test out. The original plan was to pick up SIMs in LHR, but since we want to load music onto these and use them as players, I'm looking for other optiosn.

We want to go with the O2 network since at the 15 GBP top off level they give you unlimited calling to other O2 phones, which we believe to be ideal for our situation (Unlimited between each other, and then some allowance for calling ahead or back to the states).

Does anyone have any unused SIMs for O2 lying around from a promotion or something? One comment on one of my previous threads recommended I ask that of flyertalkers since sometimes they are handed out like candy. A US origin would be ideal as we want to make sure we get them in time for the trip.

Barring that, what's the best way to obtain O2 SIM cards in the US with a delivery date no later than Oct 8th or so.

And while I'm at it, how does 'topping off' work, are cards solds in the UK that let you do this like iTunes, or do you have to link it to a credit card or what?

(We're usually Verizon customers, so the whole GSM phone and Pay as you Go plan stuff is very foreign to us.)

Thank you for all help and comments.