You can use Business Connectivity Services if data is outside SharePoint (create external content type and a list based on it). For marquee, you can use jquery (ex. with CQWP). There are also ready made 3rd party webparts that offer ticker effect (ex.
Edit: I just blogged about using CQWP and JQuery to create a horizontal ticker
You add a CEWP to the page where the CQWP is located, add reference JQuery and a ticker JQuery plugin (with CSS) and the script to the CEWP source
The plugin used is
Note: CQWP does not support External lists.
Edited byAbedKhooliSunday, May 15, 2011 8:48 AMmore details