I stumbled on a thread talking about the use of Microsoft Vista in the "Terminator: The Sarah Connor Chronicles” TV show.  Not that I spend much time on this type of activity, something struck me about this article and I read it entirely.  In the comments section someone pointed out that the name of the store and the name on the store bags were 1337.  I didn't really get it: Why is it interesting that the store name is 1337?  Thanks to Wikipedia I was able to read a full account of what makes 1337 meaningful.

Leet (written 31337, 1337, and l33t), or Leetspeak, is a written argot used primarily on the Internet, which uses various combinations of alphanumerics to replace Latinate letters. The term is derived from the word "elite", and the usage it describes is a specialized form of shorthand.

For a more practical explanation you can have a look at the (official?) 1337 web site where a more colorful definition exists. 

I'm sad to say I have never heard of this.  Now I have been in the computer industry since 1989 and had the belief that I had a pretty deep knowledge about all things computer related.  I guess I was wrong.  Did you know about 1337?