Thanks for the very helpful replies chaps.
I wasn't thinking of doing anything illegal, I just wondered if using one of the free providers would sufficiently muddy the waters for yer average internet savvy punter.
So, hypothetically of course, from your replies, am I right in thinking that you could tell a certain party that you were emailing while on a layover in New York, when, in fact, you were in a discreet hotel in Chipping Norton, and all else being equal, the party would be none the wiser.