I bought a used Mini over the winter from a member here. It's a very capable machine, don't let the size fool you. For 99% of what I do: web page coding, browsing, IM, and email it's perfect. I find myself switching over to my big windows machine less and less. I've got the 1.83 Dual Core and 2 GB of RAM a brand new mini with more RAM and faster processor could very easily become my primary computer.
I've been debating whether or not to use my current mini as a media PC or a regular computer. You can see my thread about that
here, I put it back on my desk over the weekend and have been using it as my primary computer since. Whenever I put it on my TV Stand I cannot help but feel I'm wasting a the computer as I don't use it much. Once I save up a few dollars I'm going buy a new mini, and move my current one to the TV stand, the new mini will become my primary computer.