I’m trying out this toolbar for Firefox:
Quite useful, especially if your research is mainly in the US, but it has some non-US links too. I’ve disabled some of the items – it would be great if you could customise it by adding your favourite items to the relevant drop-down. here’s the link if you want to try it out:
The home page has a wide range of genealogy links too, so it’s worth a visit even if you don’t try the toolbar.