Aggregate posts from sub-sites to the main site?

Hi, I'm wondering if there's a way to make it so when somebody posts on a sub-site that the title and few so many words will be posted to the parent site, but rather than repost the entire post, just that short version, and the titles link to the original site's post. I'm aware of the plugin here that allows you to show recent global posts in a widget, but I'd really like to have them displayed on the home page as truncated posts. Anyone know of an easy way to do this? Thanks.