Originally, I thought it meant "Sci-fi for people who don't understand Sci-fi but kinda like it". Yep, I made that up. Upon further investigation, I found that it's a genre within Sci-fi created in the 80s. Author Bruce Bethke coined this phrase in his short story featured in a Sci-fi mag. He meshed the words cybernetics and punk to describe the "bizarre, hard edged, high-tech" science fiction that was taking form in the 80s.
"Classic cyberpunk characters were marginalized, alienated loners who lived onthe edge of society in generally dystopic futures where daily life was impacted by rapid technological change, an ubiquitous datasphere of computerized information, and invasive modification of the human body." –Lawrence Person
"Cyberpunk can be intended to disquiet readers and call them to action. It often expresses a sense of rebellion, suggesting that one could describe it as a type of culture revolution in science fiction"Some relatively recent examples of Cyberpunk movies are Robocop, Paycheck, A Scanner Darkly & Surrogates. I listed the movies first because I don't know if you've read some of the books but here are some examples (chosen at random because I haven't actually read them) : Holy fire by Bruce Sterling, The Mirrored Heavens by David J. Williams Trouble and Her friends by Melissa Scott. Perhaps the most famous cyberpunk novel is Neuromancer by William Gibson.
Turns out Uglies isn't so much cyberpunk, but the it is very similar. This is such a fascinating genre to me and I hope I've inspired those of you who haven't heard of it to check some books out!
Here is a kick ass introduction into the world of Cyberpunk click here
Check out a complete list of Cyberpunk works here