I don't know about a source you can upload your videos to, but it is possible to upload them to your own server (if you have one).
In my case, there was a 3 minute video I needed to view on my iPhone, but did not have my USB wire handy. So I opened it in QuickTime, saved it as "iPhone (Cellular)", and uploaded it to my server. When I typed in the address on my iPhone, it took a while to load, and I was able to view it fine.
However, this was a 3 minute video. If you're trying to stream movies, I'm not sure how the load time and quality would play out.
Of course, this won't work for everyone, as not everyone has their own server to upload items to.