At last, one of the two things that have never been on the Big Bang Theory has been acknowledged: Ubuntu.
Sheldon: "Ahh, Ubuntu, my favorite Linux-based operating system." (I believe that was the quote, if it isn't, I'd appreciate the correction.)
Every computer nerd (and Sheldon certainly is one) uses, or has used at some point a Linux distribution. It's a small point, but it has endeared the show to me even further.
Now, the only thing that I'm waiting for a mention of is Dungeons & Dragons. (Yes, I've seen every single episode, and I'm quite sure that it has been included in none of them.) Really, a show about nerds, and not a single mention?