I have a general hatred of picking up on people at work... especially cute guys in the Castro. I can just imagine being in such a position and getting incredibly tired of all the unattractive people hitting on me all the time. (no, I'm not putting myself in the 'unattractive' bucket... but you get the idea :P)
I'm thinking about going by tonight and just asking "Hey... would you feel like hanging out for a little while after work tonight?" It feels simple and clean and uncomplicated.