Be direct

We geeks are naturally shy creatures.  It's much easier to admire from afar and carry that torch long into the night.  Unfortunately, that won't get you a date.  It's much better to say, "Hey, I think you're pretty nifty and I'd like to take you on a date."  Don't be arrogant about it, but don't beat around the bush either.  Plus it's way easier to pull this off if you haven't been carrying that torch for months.  If he/she says no, you haven't invested THAT much energy yet.