Mine works fine with my canon XSi. But beware for thumb drives its just about useless. It refuses to work with a PNY 16gb thumb drive. It's a brand new one so I figured it would be efficient enough to work.... Nope.
But it does work with my Old Logitech keyboard, one of those ones with the huge triangular wireless base. So that's a plus. Of course until jailbreak no mouse support or xbox360 controller support
Well, saying it's useless when it doesn't do something it isn't supposed to do is a bit harsh. It's called a camera connection kit for a reason.
If you want to use it to transfer files to and from your device to the file system without restriction, you MUST jailbreak the iPad and then use an app such as iFile. Head over to our hacking section and read the stickies in there for more details. The only way to get unrestricted access to the file system is via jailbreaking.