Recently I bought this cheap portable spray booth from amazon..
I finally got to use it. It's not very big, but it seems to do the job as long as you're just painting small-ish parts. The fan's not very loud, it sucks pretty good and the detachable hose that sticks out the window takes most of the fumes away as it should. It comes with a little lazy susan, so I used it to stick some stuff to that I needed to paint. When you're done, it folds up into a little box for storage (the hose doesn't fit inside unfortunately).
Overall, i'd recommend it if you've got a limited work space like I do.