I'm almost finished my PhD and would like to work in the US. Assuming I start applying for academic jobs and get offered one, how long does it take to get a visa and move to the US to start work?

Are we talking about starting the job maybe 6-8 weeks after being offered it? Or would it be more like 6 months? I can't see an employer waiting 6 months for my visa to be processed!

If anyone has any idea of what type of visa I would need to apply for as a recent PhD graduate, that would be helpful too.

see this post, should answer most of your questions

http://www.findaphd.com/students/showmessage.asp?thread=9061&cat=4&threadpage=2&newview=1

as far as the visas, your employer will sort this out
you have a choice between the more common J1 visa or the H1-B visa
The H1-B is kind of just below an immigratory viasa and is more expensive

It takes approximately 4-6 weeks for the J1 visas, possibly a bit longer for the H1 visa

If an employer employs you knowing you are from the UK, they will be aware that visas take a little time

Any more questions, let me know - am just in the process of finishing and moving out for June

Good luck

S