Derived from the words über and n00b, which are German and 1337 in respective origination. This phase refers to someone who far surpasses the usuall levels of N00bishness, I.E. a N00b on speed.
überN00b: i r teh roxxorz at halflife 2, you fags. i pwn you all with my rocketwhoring!
contributing member of society: ...I hate you
überN00b: well you're just teh fagxxorz, you tool!