I ran across this article today by John Chow talking about the more and more popular peel away ad. It's basically an ad that sits in the corner of your website and "peels away" when your visitor places their mouse over the ad.
Some people are reporting a lot of success using this type of ad. In John's article he is promoting the product for the special price of $37. While I am sure this is a good price — and I hate to step on any toes — but there is another option.
You can get a script that does the exact same thing for free. The script is called PageEar and can be downloaded here. I don't personally use this script for anything but I have buddies who do and they claim it works fine and functions properly across all standard web browsers.
I have no clue what is involved in adding this to your blogging platform (wordpress, etc.) as I use custom software that I created. I am sure it's quite easy using your systems template editor.
So there you have it, my gift to you. If anything I saved you from doing a google search and finding this yourself :)