upPrev — Next Post Slide-in Box (upprev-nytimes-style-next-post-jquery-animated-fly-in-button) free WordPress plugin

When a reader scrolls to the bottom of a post or page, upPrev animates a call-to-action to encourage further reading.

Basically, you’ll get this, but for WordPress: http://www.youtube.com/watch?v=ZTrQGhWhCKs

Additionally, you can customize upPrev to suggest navigating to any one of the following:

• Previous
• Previous, but by category
• Previous, but by tag
• Random
• Or related, using YARPP (available only for posts/pages)

You can also edit display options, including size, position and custom CSS.