When I first installed Windows XP one of the features that I really wanted to check out was ClearType, aka font smoothing. I tried to use XP with ClearType enabled but found it just too blurry to use. Not anymore thanks to the ClearType tuning tool available from Microsoft.
The page needs to install an ActiveX control to enable you to make the adjustments, future adjustments will also need to be made from the site. Hopefully Microsoft will distribute this feature via Windows Update as well.
I've also noticed that not all applications make full use of ClearType, The Bat! which is my email client is an example. The messages themselves have ClearType applied but the folder listing doesn't, switching from smooth to clean-cut fonts is bound to give me headaches.