As an official student of physics, and therefore a geek by default, I reserve the right to post something geeky, and here it is: QR codes. What is a QR code? It's one of those funny looking dotted squares that people point their smart phones at, and they're everywhere.
I decided to get one for this blog, so I checked out a few online QR code generators.
I found the QR code generator from the ZXing project to be one of the most comprehensive. OK, so you don't get snazzy graphics, but you don't have to pay for it, and they encode anything from your contact information to a calender event.
Check out the link ZXing QR code generator and get creating your own code...