To do that you will need to know the IP address that the wireless router gives to the camera, or manually set a static IP on the camera when you first set it up. Setting a static IP on the camera would be the easiest, that way you just create the bookmark on the iPad for that address and you are all set.
Doing something like this is definitely a little more taxing than doing the baby monitor route. I like to tinker, and since I'm in IT this stuff is right up my alley. Heck, I might even claim that it's fun...other people (my wife) think I'm crazy