Try this

If you're weird like me, you sometimes talk to yourself, read aloud to yourself, and make smart-alec comments out loud, although you're the only one in the room. This happens to me often when I'm online.

Well here's Instant Rimshot, a nifty little tool that you can use to give your witty remarks a little more zing. It'll make you feel like you're a wacky morning-show DJ, or on a late-night talk show.

I wish I could figure out how to install it as an application on my desktop. For now I'll just leave it in its own little window, like my own little backup comedy posse.

I found this on the Presurfer, a random-interesting-thing website I've recently run across.