I'll admit, I had to research a couple of these before I could "get" 'em.

1. A photon checks into a hotel and the porter asks him if he has any luggage. The photon replies: “No, I’m travelling light.”
2. “Is it solipsistic in here, or is it just me?”
3. What does a dyslexic, agnostic, insomniac spend most of his time doing? Staying up all night wondering if there really is a dog.
4. A TCP packet walks into a bar, and says to the barman: “Hello, I’d like a beer.” The barman replies: “Hello, you’d like a beer?” “Yes,” replies the TCP packet, “I’d like a beer.”
5. An electron is driving down a motorway, and a policeman pulls him over. The policeman says: “Sir, do you realise you were travelling at 130km per hour?” The electron goes: “Oh great, now I’m lost.”
6. Pavlov is enjoying a pint in the pub. The phone rings. He jumps up and shouts: “Hell, I forgot to feed the dog!”
7. How many surrealists does it take to screw in a light bulb? A fish.
8. There are 10 types of people in this world. Those that know binary, and those that don’t.
9. When I heard that oxygen and magnesium hooked up I was like OMg.
10. The barman says: “We don’t serve faster-than-light particles here.” A tachyon enters a bar.
11. A Buddhist monk approaches a hotdog stand and says: “Make me one with everything”.
12. What do you call two crows on a branch? Attempted murder.
13. An Englishman, a Frenchman, a Spaniard and a German are walking down the street together. A juggler is performing on the street but there are so many people that the four men can’t see the juggler. So the juggler goes on top of a platform and asks: “Can you see me now?” The four men answer: “Yes.” “Oui.” “Si.” “Ja.”
14. Never trust an atom. They make up everything.
15. How many programmers does it take to change a light bulb? None, it’s a hardware problem.
16. A student travelling on a train looks up and sees Einstein sitting next to him. Excited, he asks: “Excuse me, professor. Does Boston stop at this train?”
17. Did you hear about the jurisprudence fetishist? He got off on a technicality.
18. Werner Heisenberg, Kurt Gödel, and Noam Chomsky walk into a bar. Heisenberg turns to the other two and says: “Clearly this is a joke, but how can we figure out if it’s funny or not?” Gödel replies: “We can’t know that because we’re inside the joke.” Chomsky says: “Of course it’s funny. You’re just telling it wrong.”
19. A Roman walks into a bar, holds up two fingers, and says: “Five beers, please.”
20. Did you hear about the man who got cooled to absolute zero? He’s 0K now.
21. An infinite number of mathematicians walk into a bar. The bartender says: “What’ll it be, boys?” The first mathematician: “I’ll have one half of a beer.” The second mathematician: “I’ll have one quarter of a beer.” The third mathematician: “I’ll have one eight of a beer.” The fourth mathematician: “I’ll have one sixteenth of a…” The bartender interrupts: “Know your limits, boys” as he pours out a single beer.
22. What does the “B” in Benoit B Mandelbrot stand for? Answer: Benoit B Mandelbrot.
23. Jean-Paul Sartre is sitting at a French café, revising his draft of Being and Nothingness. He says to the waitress: “I’d like a cup of coffee, please, with no cream.” The waitress replies: “I’m sorry, Monsieur, but we’re out of cream. How about with no milk?”
24. A classics professor goes to a tailor to get his trousers mended. The tailor asks: “Euripides?” The professor replies: “Yes. Eumenides?”
25. A programmer’s wife tells him: “Run to the store and pick up a loaf of bread. If they have eggs, get a dozen.” The programmer comes home with 12 loaves of bread.

You're killing me.

Wait a minute, does that make me a geek if I at least understood most of them, haha?

Love the one about the crows.

Yes, you're a "Warrior Geek".

Nice one GnuTux.
I'm pretty sure they're a few people around here who got 100%.
I had to look up at least a handful and learned a few things in the process.

I know Benoit B Mandelbrot mostly from the Mandelbrot but I'm still struggling with, Is it B. is roughly Benoit B Mandelbrot from his "theory of roughness"?

I had to look up 2 & 24. Weak vocabulary, I reckon.

The B in Mandelbrot has to do with the way fractals work. They're a copy, inside a copy, inside a copy ...to infinity. I think of it kinda like a mirror reflecting a mirror.

"Oh, a wise guy, eh?"

I found this similar answer.
Quiz: How good is your mathematical sense of humour?
Answers: Answers to Simon Singh's maths humour challenge

While we're on the brainy jokes check #4 here, 13 Jokes That Every Math Geek Will Find Hilarious. I'll need Merrick to explain.

I can now officially be declared dead.

The answer given to number 5 is incorrect. While the first answer provides the magnitude of parrot cross banana, it fails to take into account the direction (the result of a cross product is a vector). Though it merely restates the problem using mathematical symbology, the third answer would be the most correct.

I think I must be about 98% geek - I understood most of them.

So what's the other 2%?

Nerd

erisian: at least you know yourself very well!
i understood most of them too, but my other 2% is "fantastic".

Bad eyesight here even with glasses on. I thought you put 28% and didn't think that looked right. Now I am seeing it clearer.
I only got about half.

Do you fancy "pocket-protectors"?

Great idea, thanks!