If you haven’t noticed, when you hover over external links (links going to outsite sites), it will show a preview of the page in a little popup.
If you dislike the Snap popups on your wordpress blog, you disable snap by unchecking the box on the dashboard under presentation/extras.
Other Info for Snap Users
By default, Snap Preview Anywhere only gives previews of external links, but you can enable it for internal links by inserting the code from here. Keep in mind, only WordPress users that can modify the code can do this. (Thus this blog cannot.)
Snap supports TypePad, WordPress, and Blogger.com and includes instructions on how to install the feature on your blog.
Snap can be modified to only preview or exclude designated links as well. For more information view their FAQ.