SEO Advice needed

A couple of days ago I thought Google loved me. Immediately after I posted an entry, all the keywords for this entry showed up in the very first place in Google; but my happiness did not last. My blog get aggregated by a few large itechnology portals and after a few days, Google spidered their copy of my entry. Immediately after this event, they took my place in Google and took me completely out of it. It seems like their post has more authority than mine, the content is the same (its aggregated), therefore, theirs stay, and mine goes.

Is there anything I can do about this? I'd like to keep the aggregators, but somehow claim ownership of the article. Is that mutually exclusive? Is that what micro-ids are all about? Any help would be appreciated.