Virtual Desktop on OS X

One of my favorite things about Linux is the virtual desktop. It is software that allows me to have several different desktops and easily switch between them. So, I have one for general email and web browsing, one for my Georgia State work, one for SIGGRAPH, and one for system stuff. This way I can have all my windows open and easily switch from one task to another. I wanted the same capability for my Powerbook. I did a Google search, looked around and found Desktop Manager (it's free). It seems to work just like Linux; to switch windows just click one of the 4 small windows on the task bar. It says it only works with Panther, but I am running Tiger (10.4.1) and it works fine - so far. Very nice!