Anyone have any experience using a Linux system for home security monitoring?

I currently have a little EEEPC that I use with motion and the EEEPC's built in webcam. It's just running Debian and the only reason the lid's ever open on it is for the webcam.  I ssh into it, I don't actually use it.

It works OK, it detections motion and I've configured the box to ping me a direct message when it sees things.  The built in webcam is worse than crap though.

I'm thinking of getting a couple more USB webcams and plugging them into a hub to monitor motion around the house.  It can then message me if it seens anything and snap a few frames into a Dropbox directory.  So if someone does break in and steal the laptop at least the frames have, hopefully, been uploaded to Dropbox.

Anyone have any good quality webcam suggestions that they know work under Linux?  Is this even a viable idea, I'll have to run USB extension cables around the place, ugh.

Any other suggestions for monitoring a house (from a security point of view) using Linux?  Are there any door opening sensors or similar that people know of?

I'm going to get the Twitter integration going so that I can DM a box and it'll turn the system on and off, all doable using the ttytter program.

Keen to hear about anyone using Linux for home automation things, using simple console/shell stuff.  The box is too small to run XWindows (well, it could) but I just want to be able to ssh in and control things.

Cheers,

Tim