Go to
www.digg.com and sign up for a free account.
When you see a good article on Cathinfo, click the "Digg" icon (found at the bottom of every article)
Type in a title, and a description.
After submitting the article, it will appear in Digg's network which is viewed by millions of people. Imagine people finding Catholic information because you submitted a story!
Also, once an article has been submitted, you can give it more votes -- that's even easier than submitting the story. The more votes a story gets, the more visible it is.
Matthew