I just came across a very cool use of Jetty.
The folks at IBM alphaWorks have come up with an Eclipse plugin that translates your Eclipse UI into XUL and vice-versa so that you can effectively use your Eclipse from your (Mozilla-based) web browser! Jetty is the servlet engine providing the browser-to-Eclipse linkage.
Go and check it out at: www.alphaworks.ibm.com/tech/eclifox
One slight problem is that the first release of the plugin will only work on Windows platforms, however they’re working on an update that should be platform independent.
The plugin currently requires you to download the Jetty jars separately, however as Eclipse 3.3 and onwards ships with an internally available Jetty, the alphaWorks guys may well be able to hook into that in a future release, streamlining the installation process and reducing duplication.