Tiddlyspot

"Get your own powerful personal wiki in seconds with no installation required. Make it private or public. Update it online and offline."

http://tiddlyspot.com/

Wikidot - Free Wiki Hosting

"Wikidot.com is a farm of Wiki Sites. Our mission is to provide free and professional wiki publishing, collaboration and communication solutions to anyone who needs it and wants it."

http://www.wikidot.com/

Share a disk - My Disk Server

"MyDiskServer is a small Java application that you run on the computer you wish to host files from. It requires no installation and can be launched by a single click."

http://mydisk.co.uk/

Video Hosting

" There are alternatives to YouTube. One of the most popular is Yahoo Video which has been around for some time. Facebook recently added the ability to upload videos, no doubt in an attempt to keep up with MySpace. Both of them are simple to use, but you will still have plenty of competition if you want to get noticed. Here are some alternatives to YouTube, Yahoo, Myspace and Facebook, for people who want to share their videos with the world."

http://askbobrankin.com/video_hosting.html