In biology/chemistry we like to say, "If you aren't part of the solution, you're part of the precipitate."
Honestly in my group we don't tell very many geeky jokes, though, I don't know what's wrong with us. I hope to gain some good ones from this thread!
ETA: I do puns sometimes. Actually, one pun over and over again, sadly...
Boss: I have to finish my contribution to the nanotechnology paper.
Me: At least it's a small part.
Then I crack up, and my boss looks at me like, "I can't believe I pay you to work here."
My dad loves "Tom Swifties," though. You start with simple ones:
"I just washed that window!" Tom said clearly.
Then you move on to more obscure ones:
"I'm learning about Charlemagne," Tom said frankly.
"All in all, Helsinki is a great city," Tom finished.
"That's a lovely Christmas tree," Tom opined.
I guess they're puns?