YouTube now have a basic online (browser based) video editor, with very similar tools/interface to that of either iMovie or Windows Movie Maker (It's actually using Adobe Premiere Express! - great advertising move by Adobe - they include a link to 'do more' by using Adobe Premiere Elements 3) - includes a timeline, ability to combine video, phots, music, and graphical effects (Titles, borders, symbols) and transitions! There's also a Flash demo overview. WOW!!!
"About YouTube Remixer
Sometimes, instant gratification video is just the thing you need.
If you've ever uploaded from your cell phone, wished for an easy way to add titles and transitions, or just wanted to remix your own videos, Remixer is a great place to play. It lets you assemble your new video in an easy drag-and-drop timeline, and then publish it right back to YouTube. Your original videos will stay exactly the same."
YouTube also have some other cool features: http://www.youtube.com/testtube
Finally - the mobile version of YouTibe is now live: http://m.youtube.com and you can upload videos to YouTube directly from a video capable mobile phone via MMS - every YouTube account has a 'secret' youtube mms address: email@example.com