The first few weeks, I found that after driving for 5 or 10 minutes I would suddenly realize that my body had started to lean slightly to the left (maybe this was my subconscious telling me that it wanted to shift from the right-hand seat to the left hand seat!), and I would have to straighten myself out again by leaning to the right. That seems to have gone away, but holding the stick shift in my left hand definitely still feels weird.
British drivers are, on the whole, a pretty good lot. Naturally, you can always find one or two that behave badly, but for the most part they and both skillful and easy to get along with. In both Santa Clara and in Lexington you periodically run into drivers that look as if they are just barely competent (e.g. afraid to touch the accelerator pedal, forget to signal turns, etc)-- I really haven't seen any of those types here in Cambridge. I think it may have something to do with the UK driving tests, which are quite difficult to pass.
Highway driving seems ok, although the big highways (M1, M6) seem to be very crowded at all hours of day and night. On our trip up to the Lake District last weekend we made aggressive use of the GPS, which helped a lot. We have named our GPS "Bruce" (Ethan was fiddling with the unit and somehow managed to set his "voice" to an Australian accent-- not sure how to undo that).
So far no accidents or "bumps", although I have had a couple of close calls, the closest at the main rotary near the train station (very busy indeed). The cardinal rules that I need to keep repeating to myself are: 1) keep left (duh!), and 2) look for oncoming traffic from your right (crucial for rotaries). It also helps to keep the radio turned off-- the fewer distractions, the better. I haven't had any significant "lane confusion" issues, thank goodness. In fact, the only incident I can think of was on a recent trip down Grantchester Road to the grocery store, where I came around a corner and was confronted with a white-haired elderly lady who was approaching from the opposite direction in my lane. Possible American ex-pat? Anyhow, she realized her mistake and pulled to the other side before we reached the critical juncture.
Riding on the passenger side still feels a little odd, too. It is hard to ignore the sensation that your side of the car is about to smash into something (of course it doesn't help much that most of the roads in Cambridge are very narrow, so there are lots of tight squeezes and tiny alleys where you have to "take turns" with the oncoming traffic.
