Open original link of feed posts in a lightbox

I have a number of feeds coming into the site from google alerts. The post shows a ver short extract of text from the feed article and a link string "Original Link." Cicking on Original Link opens a new browser window potentially losing the user from my site. Is there any way that the link could open in a popup, e.g. lightbox or rokbox...this way, when the user closed the popup they would still be on my site.
Thanks,
Andrew