Facebook sent an invitation recently to news agencies for another announcement coming this Monday. While there is no direct mention as to what that announcement is, TechCrunch believes that this may be a major play on a new email service, aimed at competing with Google's Gmail service. Based on the invitation image, it seems likely that the announcement has to do with messaging, since that's what the graphic shows. Then, references to a secret project called Project Titan came up again recently. Finally, just this week, we reported on how Google and Facebook have started an all-out war concerning the exporting of contacts and friends information. It's all still rumors for now, but it will be very interesting to see if a Facebook based email service would take a big chunk out of services like Gmail. Since Facebook has done everything it can to become your primary contacts platform, it would sure make a lot of sense.