Well, I have the plug-in keyboard dock for my iPad, but one serious limitation of that is you're stuck in portrait mode, limiting your screen space. I don't like that. So I ended up buying a Microsoft Bluetooth Mobile Keyboard 6000 yesterday that works great. That was an interesting story. Let me tell it, literally as verbatim as I can remember.
Me: *walking into national office supply store chain, to woman who works there who'd just asked if she could help me* Looking for a bluetooth keyboard.
*Note, I didn't have my glasses on, so I had to squint to read.*
Her: Oh, let me get Bob (or whatever his name was) to help us. *She flags kid over.*
Me: I need a bluetooth keyboard for my iPad. *By this time I'd squinted enough to spot a sign over his shoulder that said "bluetooth" on one of the keyboards on display.*
Him: We don't have any bluetooth keyboards.
Him: Nope. Sorry, we don't sell them.
Me: *pointing* What's that?
Her: *laughing* Looks like it says bluetooth. *Mind you, she works with him and is enjoying his fucktardary at his expense.*
Him: *frowning* It won't work with a Mac. It's for PC only.
Me: *grabbing box from other woman who obligingly handed it to me* It says here it'll work on Macs or PCs.
Him: It won't work on your iPad.
Me: *arching eyebrow* Why not?
Him: It just won't. But you have fourteen days to return it. *slouches off*
Needless to say, I bought it, it works fine. Ironic it's a Microsoft keyboard and works on an iPad. I like that. It suits me.