Beware, varies form state to state, but I bought one in Colorado, with a UK license and a US address. Got screwed with insurance, but still works out cheaper than renting and less hassle than public transport. California has emission tests you need van to pass before you can get a license, so watch out.
PS a lot of people carriers have seats that fold down to form a comfortable bed. I found this out as a bonus after I bought a Ford Aerostar, which was super reliable apart from a really rough road (my fault) making the seal on the transmission fall out. Easily repaired though.