I've noticed a lot of Americans moving here to Dublin, Ireland the past few years - most seem to be 30+ though and career focussed. I suspect younger Americans are attracted to destinations like California, China and Continental Europe.

I guess Americans who don't mind the rain and grey skies would find it easy to settle here - English speaking, high quality of life, great education prospects for children. I have to say though tech wages here seem to be about half what they are in CA but even within the US, tech wages are much lower than CA.