StumbleUpon is very popular social Web 2.0 tool which started here in Calgary by a post grad student.It's a pretty cool tool and StumbleUpon (now owned by Mozilla) plans to make similar programs.
If you don't have StumbleUpon my advice is get on StumbleUpon. Now. Then make me your friend. When you go to StumbleUpon you will have to register and set up an account (it's free). You'll have to enter some personal details, such as your user name, personal interests, you'll also have to enter a password. Then once you've installed the tool you have a toolbar at the top left corner of your web page. Click tool and it'll take to a neat site. Then you're ready to go! Then later - make me your friend. No really.
If you're excited about trying out StumbleUpon, please click on the logo below: