Turn your webcam into a surveillance camera. HomeCamera software allows you to automatically record, get stills or videos from your webcam from any browser, including your cell phone, and a host of other features. Motion detection options can even alert you by email. Currently the beta is free, but they plan to always have a free version along with a full version at $14.95/yr.
I found a few other sites that are completely free but I don’t know the details on them. If you’re interested in this project, you might check these out as well: