There’s been some talk lately about GUI focus-stealing:
I have definitely been bitten by the focus-stealing pop up. Once I unintentionally rebooted my PC (during the early days of Windows Automatic Updates). I was mad as hell. Another time I accidentally typed part of my password into an instant-message window and sent it. GRR.
I think the Firefox team has done great work in this area, and I’m surprised nobody has mentioned it so far. Here’s a screen shot:
See the install button? There is a “3…2…1″ countdown before it gets focus. Brilliant.
Please people, I implore you: steal this idea.

And you are using Adblock Plus! I haven’t seen ads in forever :)
Actually Azeem, that was just the first link I saw at mozilla.org. I actually don’t mind ads too much :)
There is an add-on you can install that lets you change that focus timer length as well. I don’t remember what its called because I don’t mind waiting 3 seconds.