for anyone going to USA for a holiday and wanting cheap & cheerful net access, the T-mo PAYG SIM + sidekick $1/day plan + Tor (from extras-devel) is really the IDEAL solution.

In April I went NY - Virgin Islands (US + British) -> NY -> LA -> San Fran -> LA and (except for a couple of days in BVI) I had uninterrupted 3G web access the whole way for $1/day.

Skype out (even on a yacht in the carribean, on 2.5G and with Tor enabled) worked seamlessly - though I later realised that Tor wsn't needed as Skype was happily transiting the T-mo firewalls without any need to enable Tor. I even had Tor configured to give a UK exit point and was able to fire up iPlayer in my hotel room (over wifi) to catch up on a crappy show that the wife was b!tching about missing :-)

Like Geneven says - it's a no brainer, just pre-install Tor, go buy a SIM and have a play. Being able to fire up assisted GPS while roaming, make skype calls whenever you want, and receive incoming calls to/from US callers on your US cellphone # without the horrendous international roaming charges you get on your domestic # .... what's not to like? Just pop your own SIM back in the phone every so often in a wifi zone to check for any missed calls/texts. Simple :-)