Well, I'll tell you the story, but it's not that interesting.
I was talking with a friend about the name for a blog. My first conception was a website where I posted lots of tiny bits of code, centered around Web 2.0.
So, lots of little bits of Web 2.0. Hmm, "bit," like bits and bytes. Then I thought of Web 2.0 tropes and came up with 20bits since that was the trend (37signals, 30boxes, 43things, etc.)