Before I spill an enormous trade secret here, I want to give a midget lesson, because such things are fascinating to me. Hopefully, your next question would be 'How do I decipher a URL, and what meaning does it have for me?'

If that indeed is your next question, then you are in luck.

The '?' mark in a URL signifies that information is being passed in the URL itself. For example, imagine you have three kids named Bill, John, and Sam. You want to tell your neighbor publicly how old your three kids are. You would say that Bill is 3, John is 6, and Sam is 7. If you wanted to tell your neighbor all this information in a URL, you would do it like this.

http://www.example.com/? bill=3 & john=6 & sam=7

(spaces have been included to make the URL easier to read)

The question mark means information is being sent. Bill, John, and Sam are variables (easy to remember names to use and access the data). The data in this case are the ages of the three kids. The variables (the kids names) make this information easier to access. The '&' sign means more information is being passed strings everything together.

Here comes the fun part. I was wondering if it was possible to sign into Gmail without activating chat. I didn't want to have to disable the chat setting everytime I signed in, etc.

Anyway, I wondered if Gmail chat could be manipulated through URL variables. So I typed this into the URL bar. 

http://mail.google.com/mail/?chat=0

The variable here is 'chat' and the data is the number 0. If you are still with me, then you may be wondering why I used a 0 there. In coding, 0 is equivalent with 'false' and 'false' is equivalent with disabling features, etc. So by guessing 'chat' was a valid variable and setting it to 'false' (0), you can sign into gmail without enabling chat. If you use the regular URL (http://mail.google.com) then chat will be enabled like always. Cool huh?

So try it right now, click on the link below and watch as your Gmail loads with no chat box at all. Amazing!