Alfredo (aka K2K9)
This was a robot built by me and renatose in past September at Campus Party Europe in London. (I know it's a bit late).
After some drinks in one of the nights we decided that we should build a robot with the empty cans we had. However the security guards didn't tought it was a good idea to let us enter the event site with two plastic bags filled with empty beer cans at 3 am in the morning and after about ten minutes Renato agreed to put the cans in the trash.
In spite of that, we wanted to build the bot anyway so we started going around the tables asking people for empty bottles and finally got enough material to start working. We used four coke bottles as the legs and a pringles can as the body.
In terms of electronics it had 5 micro servos, one for each leg and other for the tail and three sharp sensors, one pointing front and two for the sides so we could "pet" it.
It could sit, give the paw, lean forward and also walk, but only if we pulled him using the power cord.
It was really nice to walk him around as people loved to play with it, specially the girls :-P
EDIT: On the video the sensors weren't being used, so here is another one, shot by someone else: http://instagram.com/p/d-AyJbnmDD/
Oh, and those eyes, who can recognise them?