Spybot - Search and Destroy Updater will allow you to update your Spybot S&D detections without the need for the included WebUpdate.
Spybot - Search & Destroy can detect and remove spyware of different kinds from your computer. Spyware is a relatively new kind of threat that common anti-virus applications do not yet cover.
If you see new toolbars in your Internet Explorer that you didn't intentionally install, if your browser crashes, or if you browser start page has changed without your knowing, you most probably have spyware.