I came across a wireless Network Surveillance Camera for $60 on sale a while ago. I ordered one and set it up...
It is a surveillance camera that you can connect to your computer through ethernet or wireless via your router.
I don't want to post photos of my house, so here is the same camera setup as a webcam: Wireless IP Web Cam How To
TRENDnet TV-IP100W-N. Reliability has been good. Wireless range is the same as my home network- max of about 40 feet indoors. Nighttime video is not great, but coupled with a motion detector light, it is fine. It is intended to be used inside (optional $100 exterior box) but I just put it under my overhang. It will stay dry...
Newegg.com - TRENDnet TV-IP100W-N 640 x 480 MAX Resolution RJ45 ProView Wireless Internet Camera
The software has motion detection so it only records when there is activity. You can also set it up to email you photos of the motion. Vitamin D is really quick to review the footage. There is a free version or you can buy the 2 camera version:
vitamin d : home
I used to use:
It is quick to review if someone is at the door and comforting to know if someone breaks in, there will be some sort of record.