On the other hand of the worst things (as far as productivity and a social life goes) is the ability to print anything you want. Especially given the plethora of incredibly cool and yet generally pointless things on the wonderful website, Thingiverse.
It was here that I found a lovely design for Tony Stark's Arc Reactor from the film Iron Man. I saw it, and I knew there and then that I needed to make one. I printed the majority of parts in Black PLA, and the crystal in Clear. I get all my PLA these days from Faberdashery, it's reasonably priced and of a really high quality. I bought a selection of blue and white ultra-bright LEDs from eBay, along with a few resistors and a 9V battery clip, and did my best to remember how current, voltage and resistance interact with one another. It wasn't as straightforward as I remember it being. Eventually, a few blown LEDs later, and with a large burn on my thumb from where I'd tried to pick up some solder that, as it turns out, was still molten, I had my very own Arc Reactor.
My thirst wasn't sated with that however. Another trip to eBay and I had a strip of elastic. 30 minutes on Google Sketchup and I'd designed a nice little belt strap. Taking a pair of scissors to old t-shirt, and my costume was complete. I was Tony Stark!
Unfortunately, no-one's having a party any time soon with a suitable theme.
Also, I can't grow a beard.