I have no wish to go to the US, let alone live there, but I am intrigued that other Abers say that UK residents will find it difficult to get a visa or residency. Why? We are supposed to be close allies - (although I always get the impression Americans are only out for themselves). Do other nationalities find it easier?
These are the conditions under which a British citizen can apply for permanent residency in the US. http://www.usembassy.org.uk/cons_new/visa/iv/i ndex.html
As you can see it would be rather hard to get one of these immigrant visas. Citizens of some other countries (including Ireland) can apply for the 'green card' lottery. This picks so many people a year who have applied, to 'win' a green card meaning they can live and work in the US. Why British citizens can't I have no idea.
The reason Brits are not eligible for the green card lottery is that they have a much better than average chance of getting a visa 'legitimately' than many other nations.