Here is a video of a custom automated home defence USB BB gun web cam system. The guy in the video built the system and wrote the automation software. He demonstrates firing the BB gun inside his house and through the window.
Guy puts on a skydiving wing suit, straps a jet engine to each of his feet, and jumps off of a hot air balloon for a good time in this video. It doesn't look like it would be very easy to land with the jet engines on his feet but I assume he just pops a parachute.
Here is a video of a stair climbing mech suit which appears to be built out of car shocks. The video shows the mech like chair unit climbing down stairs and then walking across the floor. There are two guys standing to either side to catch the guy riding it if it falls over.
One of the most emailed photos on Yahoo today is this photo of a giant strawberry shaped cake. Apparently they made it in the Philippines and it won the Guiness World Record for being the largest fruit shortcake. The woman is cutting the cake with a sword. It doesn't list what the cake is made out of on the caption for the photo howerver.
This demo reel video shows a "dragonfly" like remote controlled robot. It is about the size of say a pigeon and looks like it is made out of styrofoam. It flaps it's wings but it also has two very small propellers on either side. Apparently it is a buyable product and not just a prototype.
In this video the camera is mounted on a model rocket facing downwards as it launchs. It looks like they launch multiple rockets at the same time from the smoke trails. Also if you look at 0:11 in the video it seems like either the video distorts or the fins on the tail of the rocket turn into jelly for a few seconds before reverting back to their static positions.
In this interesting video they demonstrate a working orithopter model which flies around a school gym. A orithopter is an airplane that flats it's wings like a bird. It's hard to tell what is powering the flapping wings in this video. It could be a rubberband or a really small battery motor.
This video shows off a prototype of a house building robot. The robot has a pattern that it follows and it just builds one layer on top of another by laying out material (like concrete) and contouring it. The initial robot in the video is a small prototype which seems to be using clear and near the end of the video it moves to larger prototypes using concrete.
In this video a guy demonstrates an accordion chair coach. It seems like a bunch of pieces of cardboard or similar material in the shape of a chair which is attached togather like an accordion. It seems pretty light.
In this video they have a wiimote controlling an industrial arm robot. The two different things they try are attaching a tennis racquet to the robot arm and attaching a sword to the robot arm. One noticeable thing is that the robot arm lags considerably behind the wiimote movement.