In reply to control freak:
alicia was referring to me. I am currently doing a postdoc in the US. I am not exactly sure about looking for postdocs in the field you are interested in, but higheredjobs could be helpful. The way I have applied for postdoc positions in the past (this is my second) is to look at faculty who do stuff that I am interested in - and then just email them directly. It does work reasonably often, I would say (of course, only a handful reply back). As far as administration - well, it is, as alicia mentioned, probably not that much different than the UK.
Moving - well, in my case, it required putting all the stuff in my car and start driving towards the new job - of course, this exact procedure may not work that well for you from across the pond. But seriously, most of the time I have just moved to a new location and then tried to find a place to live - but then I only moved to relatively smaller cities.
Life - well, that really depends upon your postdoc advisor (if postdoc is the path you choose). I have been quite lucky in that regard - none of my advisors have particularly cared if I suddenly disappeared from the office for a couple of days to go climbing (as I have often done - just ask alicia).
As far as finding a teaching/faculty post - that is quite a bit harder than finding a postdoc. I am in the process of trying to find one. But, perhaps, it is hard in UK too.
I am not sure what else information you are looking for - feel free to email me at divesh.bhatt at gmail (I seldom check this site). Good luck.