This morning I run across a new blog post on the IE blog (written by Dean Hachamovitch - General Manager, IE) about things you didn't know you can do with IE8.  I must say I did know most of them already, but if you're new to IE 8, this is a good starting point.  especially the part of Sessionstorage and how to open 2 webmail accounts at the same time.

Read everything here : http://blogs.msdn.com/ie/archive/2009/05/12/ie8-nine-things-you-didn-t-know-you-could-do.aspx