That's a folder in my bookmarks. It contains all the sites I find useful in a slightly sneaky sort of way.
So in case you were all wondering.
Convert Files - This nifty little tool lets you upload, convert, and download files (though not always in the best quality). It also lets you download videos from quite a few video-hosting sites, like YouTube. Which is how I watched YouTube videos back in the days of Jorund, my old computer. It takes a while, but is mostly reliable, so I still like this 'un a lot.
YouTube to MP3 - This essentially performs what its name says, converting YouTube videos to mp3 files that you can download. It's useful, but I liked it a lot better before it got all fancy and advertisement-happy. Convert Files (above) also has a convert-to-mp3 option for videos, so I tend to just use that.
Video Toolbox - A pretty nice video-processing website with a lot of cool functions like adding watermarks, embedding subtitles, trimming the video, etc. It works but not all the time, at least not for my computer. Sometimes I try to upload a video and it never uploads.
Site2Pic - I actually haven't used this, but it gives you a screenshot of a site from a URL, plus a link to that image. I used to use Aviary's Firefox extension for that function, but it doesn't work anymore, so I might use this sometime soon.
sleepyti.me bedtime calculator - I LOVE THIS ONE. It calculates sleep cycles and tells you when you should try to fall asleep in order to wake up feeling refreshed at the time you need to, because it'll be at the end of a sleep cycle as opposed to the middle, which makes you feel groggy.
media.io - Another conversion site, but this one just for audio. I like it because it has a neat, compact interface, and also because it works really quickly.
Dropbox - Basically allows you to access the files you upload into Dropbox from anywhere. You can work on the files on multiple computers, and it'll sync the updated versions to all connected computers after you're done.