1- RadBox
Radbox is a great web tool that allows users to easily add online videos to a queue and watch them later on a computer, smartphone, tablet or television. It requires a sign up.
2- Pinterest for Videos
Pinterest has now a service where you can pin the videos you stumble upon online. You can organize them into visually appealing pinboards and access them whenever you want.
3- Skyloog
Skyloog is a great bookmarking service where you can visually organize your bookamrks including videos and documents.This tool is completely free.
4- Pause for Later
This service lets you mark a pause on a video and save it to your Pause for Later account to watch it later on. Next time you want to watch the video you saved, the video will start playing in the same spot you left it.