I have a new article on the SSIS Developer Center on MSDN, focusing on Data Sources and Configurations as tools for connection reuse across sets of SSIS packages. I wrote it months ago (looking at it now it seems even longer) but it just made it online today.
Check it out here: http://msdn.microsoft.com/en-us/library/cc671619.aspx
This is actually one of a set of articles by SSIS-focused SQL Server MVPs that will be published over the next week of so - I just could not wait to let people know that it was out there. I'll post links to all of the articles once they're all online (and I probably won't be the only one to do so) but for now you can get started with this one. Enjoy!
 For example, the "about the author" blurb at the bottom lists me as still working at Configuresoft, even though I have not been working with Configuresoft since the end of July.