This is where the world's most beautiful interface comes into play...the Monome. I don't have one yet, it's first on my list to buy as soon as my $40 augments. Created out of Philly by Brian Crabtree and Kelli Cain, this minimalistic interface is focused on delivering well, just that...a minimalist's approach to open source hardware. They provide us with three Monome options listed as the Sixty Four, the One Twenty Eight, and the Two Fifty Six. Each of which comes with the buttons sized on different grids: 8x8, 16x8, 16x16. The Monome is purely, 100% "buttons," as well as purely, 100% blank, adaptable opportunity. This may seem intimidating, I admit I'm somewhat skeptical at how well I am going to able to implement my developed software.
The one thing I find exhilarating about this project is how incredibly versatile the Monome can potentially be. Let's say in fact you purchase the Sixty Four. You now have 64 buttons to program however you choose. Obviously I don't have any examples of how I have implemented any software with the Monome because I don't have one, but a mild amount of research can yield some stunning results/videos as to what the Monome has to offer in terms of adaptability and usability. There's a good sized community developing for the Monome. The majority of which are developing software within Max/MSP or Pd. The serial protocol transmitted through the USB from the Monome has to be translated into OSC (Open Sound Control) or MIDI. Once this is done, you can begin to use this data as the basis of your development. Use Max/MSP, Pure Data, Java, ChucK, Phython, etc, whatever... the point is there are a large amount of programming languages that support OSC and MIDI data.
Some may say this aspect of programming presents itself as a con, yet I think that's where the fuel of your creativity can start to boil. With a Monome, your not settling for a conventional device layed out with a manual and concrete uses, you can continually use it in a hundred different ways if you please!
Again as I said before, search for some videos and check out how other people are creatively using this beautiful interface.