Carter

This plugin takes the 5 latest posts from the FrontPage category and rotates their titles and excerpts using a JQuery scroller. Based on <a href="http://www.learningjquery.com/2006/10/scroll-up-headline-reader" rel="nofollow ugc">Scroll Up Headline Reader</a> by Karl Swedberg.
User options allow setting custom width and height. Timing and direction of the scroll cannot currently be set by the user.

Simple Headline Rotator

A simple headline rotator that uses JQuery and pulls data from the FrontPage category.

potasiyam

This plugin adds a ticker which shows recent posts as headlines. You can set the position top or bottom, fixed or absolute or set the number of posts to show. Some pretty neat features yet to come.

Just Ticker

Adds a ticker bar to your wordpress site which will show your recent post headlines.

Simple Headline Rotator vs Just Ticker