A lot of websites/blogs using page peel/page curl to add additional message such as advertisements at the corner. There are a lot of scripts that can achieve this function but unfortunately these scripts are not free.
Recently, 1 of my client requests me to implement page curl on his WordPress theme. So, I search through the internet and found some free and extremely simple ways to implement it.
1) Simple Page Peel Effect with jQuery and CSS by Soh Tanaka
2) The Sexy Curls jQuery Plugin
3) jQuery Page Peel 1.2 by Smpl Multimedia
4) How to create a page peel advertisement in WordPress
5) WordPress Page Peel plugin
The first 3 methods using jQuery while the last 2 methods use flash to achieve page peel effect. Using Flash to achieve page peel will have better animation, while using jQuery will have smaller file size and load time.
So, it is depended on yourself to choose which method to use.