Haloween costumes. A good one can take time to put together.
The kid loves Harry Potter. We've already got his costume. The whole bit, glasses, wand, Gryffindor sword, etc. I'm putting on my old black robe from graduation and will have a gnarled old staff, a bejeweled dagger, some pouches and a grimoire. Perhaps even get a cheap rubber imp and fastened it to my shoulder.
IMB has an ad campaign filled with nerds and geeks. You can get some inspiration there.
I am probably going to a school that is heavily funded by IBM and after that I will probably work for them with a starting salary of 75,000$. . .oh did I mention I get my masters degree in 4 years instead of just my bachelors?