I just finished setting up a build server for Rhino Tools. Ideally, I want it to be publicly accessible, and have people download the build artifacts after each build. However, CC.Net is not something that you want to just expose to the web. It has no security model (any random Joe can just start a build, hence DOS).
I should note that anything that involves significant amount of time is going to be answered with: "Great, when can you help me do that".