Ask HN: how to setup a US company/bank account

I know that there were already many discussions about payment gateways and comparisons between US/Non-US solutions but fact is that for many nice solutions a US bank account (and often a tax ID) is needed.

Also I just wanted to get (more out of curiosity) my feet wet with Win7 mobile apps and despite the ridiculous signup process they also restrict selling apps to US entities (like android did for a while). Also things like Amazon payments and Google checkout only work with US bank accounts.

I have seen some trustee services in Delaware that offer incorporation for overseas companies in the US but it seems a bit pricy for a couple of test apps and the odd idea i want to try out.

Are there any ways to get a US bank account from overseas without having to go through a full incorporation? Is there an easy (cheap) way to get a US company registered from overseas? I am not too fussed about low tax rates or anything - it is really only for testing out markets and ideas.