You'll no longer be sitting beside that sexy marine biologist dressed up as a sea anemone wishing that you could have a research themed costume too.
Finally, there is a combinatorics themed halloween costume! Sport this beautiful Arduino and LED based rendition of Cool-lex combinations (research by Aaron Williams and Frank Ruskey), and show off your nerd times 2.
Here is the technical stuff on the combinations:
I used adafruit's LDP6803 LEDs. There are tutorials on how to use them on that page.