Not sure how many of you have seen this yet, but this is one of my favorite new Kickstarter projects. I did a quick search and didn't see it posted or mentioned here before, so I figured I'd share.
Pressy is a button that plugs into your 3.5mm audio jack and allows you to assign any number of actions to button presses, and combinations of long and short button presses. Paired with something like Tasker, the possibilities are endless.
In my plans to permanently mount a Nexus 7 in place of a head unit in my car, button relocation became a bit of a challenge, or at least, something to think about. Sure, I'm already going to be pulling apart some of the Nexus for the install and I could take apart the current buttons and solder in some wire to extend them, but that's a bit of a pain in the ass, and it involves mutilating the tablet a little more than I was hoping I'd have to (right now I just plan to relocate the USB/headphone jack board and that's about it. USB ROM gives me volume on the screen, so that's taken care of, but the power button remains hidden. With Pressy I'll be able to turn on and off the screen as I so desire (in case it gets a little bright at night or something), as well as do countless other useful tasks like launching my music player or GPS without taking my eyes off the road and having to look for the icons.
There are all kinds of other cool uses like making it a camera button, answering calls, replacing a broken button, whatever you can think of. Hopefully I don't sound like too much of a sales pitch, but I was already interested in the ability to add a programmable physical button, but then today I started thinking about how to integrate it into my N7 head unit project, and I got even more excited over it. The price is definitely right for what it can do, so check out the kickstarter page for more info and pics.