I use Read It Later for saving webpages, but if those pages contained video's I had to visit the webpages, load the video etcetera... It simply does not fulfill my needs for watching video...
While searching Google I discovered RadBox, which does exactly what I want: use a bookmarklet to save video's to watch later. They offered an API and RSS-feed of my video's so I decided to build my own based on App Engine. Below you can find two screenshots of my basic application:
A basic interface for watching video's:
If the video is not from youtube, an iframe will be loaded to access the website from RadBox itself to embed the video and you can start from there. I wrote this with my small knowledge of python and GAE and I sadly don't yet know how to make it scalable. I can share my crappy source code if you want me to ;-)