If you use Youtube, megavideo, Metacafe, Veoh and any other sites, then you will be interested to know that there are a number of sites that give a free service to download videos posted online. All you need is the video URL and the site will download it for you. This is great if you have found something you want to look at before it is removed from the site, or you just want to keep your own copy.

The following sites offer a free service to download videos:

Clipnabber - Just paste in the URL and you can download videos from Youtube, megavideo, Metacafte
etc. You will then be given a link where you can download the file to your computer.

keepvid - My personal favorite, very simple to use (as they all are) just paste in the url and download. The site also shows the top current downloads so that you can see what everyone else is downloading.

Video Downloader - Paste the URL, you can download from any site, you can even add in a Firefox extension, this site is free but they do accept donations to help with their costs.

Vixy - Paste the URL, you can also choose which format you want to download the file into (great feature!).

I will keep updating this when I find any new sites. If you know any good sites, post a comment, I will review it and then include any good ones in my list.