New sketching goodies hit the shelves at UI Stencils, from our good friends Design Commission. They've created an iPad dry erase board with dot grid, and updated their awesome iPhone sticky pads. Definitely want to get my hands on the dry erase board.
Update:
Mine arrived and I have to say that this is the nicest dry erase board I have now. It's made on hard particle board, similar to what you'd find on a clipboard, so it feels great in the hands. There's an interaction key laminated to the back with gesture symbols and common icons, to help you while you sketch. It comes with 2 fine point dry erase markers with eraser heads that work well.
I'm loving it, and so is my son, who plans to use it for stop motion animations. I'm not working on iPad design right now, so I'd love to have a few screen and browser dry erase boards, or a 6-up/8-up sketchboard for thumbnail sketches and storyboards.
http://www.uistencils.com/products/ipad-dry-erase-white-board