Sharepoint can be a very useful collaboration tool but if you are stuck with WSS instead of MOSS you might find yourself wishing you could do more.
Your organization probably won’t let you just start coding up .NET and sticking it anywhere you want in your site. So if you are looking to enhance your user’s experience, you might want to look at this jQuery JavaScript library that allows you to access Sharepoint web services.
A couple of scenarios I have used this for include retrieving attachments for list items and seeing if a user had a record in a particular document library.
This really just hits the surface of what this could do for you. You can even use CAML to build queries to pull custom data sets.