How Do I Control My Mac From My iPad Or iPhone?
There are several iPhone and iPad apps that allow you to manipulate your Mac. Our personal favorite remote control is Rowmote Pro. It serves as a remote, but also emulates the trackpad and keyboard on your Mac. And it allows works with your Apple TV (although you will have to jailbreak it).
Another option for power users is iTeleport VNC. It's quite a bit pricier than Rowmote Pro, but it has some extra features that might make it worth the added cost for some users.