Installed home surveillance systems can cost thousands of dollars, they are expensive to maintain and costly to upgrade. Lying around your house right now you've probably got all the ingredients you need to create your own video surveillance system for next to nothing - all you need are a couple of old web cameras, a PC and some new free (as in freedom) Windows software called iSpy.
Sometime back I gave a pretty strong pan review of a couple of "toys" that were not compatible with GNU/Linux -- with open standards really, since the community ensures that free software is compliant -- and were therefore nothing more than a disappointment to my kids. Recently, I fully expected to repeat this depressing experience when my brother-in-law gave my son a "Flip" digital video camera, but I was pleasantly surprised: it works exactly as it should. That seemed worth a column in itself.