I have been considering trying this with my iPad as well.
You can buy a D-Link DCS-930L wireless Day/Night wireless camera from Office Depot, Staples or Best Buy for like $79.00. These are indoor cameras so you could not mount them outside unless you can find a housing they fit in. I have several of the Day/Night cameras mounted in housings around the outside of my house for security.
D-Link Products - DCS-930L - mydlink-enabled Wireless N Network Camera
My Cameo has a large window in the back wall. I have thought about using double sided tape to stick one of these to the window looking backwards and plug it into the 5 VDC outlet near the TV. I have converted and old cell phone charger (5VDC) to power the camera.
I have a spare Linksys wireless router I could use, just need to figure out how to power it. Guess I need to get busy and try it.