One great feature for WSS 3.0 is the e-mail enabled libraries. It can really get you using SharePoint beyond just a normal web site. But did you know that you can have e-mail-enabled document libraries using WSS 2.0? Yup, you sure can. It actually isn't anything new for the recent version.
Here is the information on TechNet: Configuring E-Mail-Enabled Document Libraries (Windows SharePoint Services 2.0)