I know this is a Liverpool genealogy forum but there should be a few people with an interest in the US.
The big news in case you didn't know is the impending release of the 1940 US census to the public (on 2nd April 2012 I think)
I have a living aunty born in the 1920s who went to America. It would be amazing to be able to find her in it but I think she is just a bit too young.
I thought I would have to use Ancestry to access it http://www.ancestry.com/1940 but it seems Brightsolid is another possibility.
They have launched (as a beta) https://censusrecords.com/ which will provide access to 1790 to 1840 for free and pay as you go for 1850 to 1940.
There is a BBC review here http://www.bbc.co.uk/news/uk-scotlan...iness-16858504
I suggest you also read the excellent LostCousins newsletter for more info on the census and other family tree stuff http://www.lostcousins.com/newsletters/feb12news.htm