The FT has an article about my pals at AlertMe. (They have a fun product – low-power wireless devices that monitor your home and can report back to you in a variety of ways. We have one of their early kits in the CamVine office.)
The article talks about the benefits for a UK startup of getting US-based funding, something we also did for DisplayLink in the early days. I suspect, though, that the relative speed with which they accomplished it is more down to the nature of the funding round, the particular fund they attracted, and the fact that there was only one investor rather than several, than it was to a real difference between the US and UK.
With CamVine, I decided to go for Angel rather than VC investors for the first round, and even stayed clear of Angel groups. I think dealing with just a few individuals made everything much easier. Perhaps we were just lucky, but we got a great group of investors… from this side of the Atlantic!