A Video Editor of some kind?

VirtualDub is as decent a video editor as you're likely to find, but its usefulness on a flash drive depends upon which codecs are installed on the host computer. If it could be altered to work like VLC (codec-independent plugins) it could be a lot better in the wild. I'm not sure if there is a viable portable solution if you need certain codecs. If it had ffmpeg alone it could do quite a lot.

Portable Firefox will let you upload to YouTube at youtube.com. Unless you have a format they can't convert somehow, let them do the work. If you don't care about quality but you want a quick(er) upload, and you can use VirtualDub and ffmpeg, you can convert the video to, say, 320x240 Xvid/AVI or Mp4.

I actually don't know a whole lot about video encoding. I just know some of the basics. They certainly don't make it easy.

There is Avidemux on the test releases page but it hasn't been updated for some time. Also its known to leave a folder behind in the USER/Application Data folder. If you like Avidemux please let alpha1 know (The porter) so it will hopefully niudge him into updating and fixing the bug.

Hope this helps

what about wax video editor?