I have one of these monitoring the front of my house / garage and can't fault it.
Anything that moves and it will take a picture and email it to you. You can also view it live via your PC on your LAN, or from anywhere in the world.
I chose this one as it's got pan and tilt you can control from your PC. WIFI pan and tilt versions cost £200 plus .... mine was only £60 but the price has gone up.
It works unbelievably well for 60 quid and has a bucket load of settings to play with including the sensitivity of the email trigger.
http://www.amazon.co.uk/TeckNet-IP-c...9559885&sr=8-3
---------- Post added at 19:23 ---------- Previous post was at 19:22 ----------
Oh ... they're called 'IP Cameras'.