Don't forget to bring an "Apple" for your computer!

Or a notebook with pictures of apples on the cover for your Apple Notebook computer.
• Maybe have a can of "chips" for a pun on computer chips - a big bag of chips, and then a snack size can of Pringles= Micro-Chips. When you're done with the props, you can take a "Mega-byte" ---- Mmmmm

.
Of course, these puns will go over better if the office is technically oriented in nature.
• Ask them if they know what Ethernet is. If they give you an answer, tell them that all this time you thought it was something used to catch the
EtherBunny.
• You could bring your own Net, so that you can connect to the net.
For more ideas, you might try reading Dilbert comic strips. Not that I'm suggesting stealing someone else's joke, but I never understood Dilbert until I started working in a cube farm in corporate America. So, Dilbert will put you in a good mindset for the Truer-than-you-know comedy.
As far as your stiffness goes, play it out. Accentuate it. Over play it.
"Yeah, i used to work in a cube farm like this, ... until that bizarre copier accident..." (then exaggerating your limp, or whatever).
Shyness? Same thing. A shy clown may get more response out of any quick quip they do because it is unexpected. But don't be so shy that you don't get involved. It's a fine line.
SME is usually all over the board - Shy when needed, Compassionate when required , but usually playfully obnoxious.
Good luck and have fun with it!
8)