Free WordPress Strx Magic Floating Sidebar Maker pluginFree
If you have a classic column site structure, this plugin will make your sidebar follow your visitors while they scroll up and down the page.
Increase ads earnings making them always visible to the user, even when writing a comment on bottom of pages. Let visitors click on sidebar links without having to go up, at the beginning of the page
See also: Official Blog Post
Source from: WordPress.org