Jaycut
Jaycut is a brand new site i found recently to edit videos. It's all online and free so no need to download anything (good old cloud computing). I have found this site extremely easy to use, you just upload a video or even a series of images, trim videos is as easy as dragging a handle. You can add audio and even transitions. I experimented with uploading some pictures and making it into a video and found it very easy to use.