How can I stream files to my iPad? I have loads of videos and music on my computer, which I want to watch on my iPad. 

However, I want to stream it to it, so I can grab what I feel like watching rather than having to preload everything.

I would like to stream these over wifi and they should be Windows 7 compatible
I'm very happy with Air Video(*). Lifehacker have a feature on it.

(*) Have only used it on an iPhone, no iPads in Sweden yet :-(