Victor Zuylen from Killzone.com writes on the Official PlayStation Blog:
"With Killzone 2 receiving lots of positive attention from the press, I figured now would be a good time to give you a taste of the bonus content which can be unlocked on Killzone.com through the game.
After you’ve uncovered a piece of Helghast intel in Killzone 2’s single player campaign, you can connect to Killzone.com to claim a special reward. These unlockable rewards come in various shapes and sizes – some are simply printable versions of the propaganda posters you see in-game, others contain details on the wildlife of the Maelstra Barrens or pages from a Helghast soldier’s secret journal.
(Please note: you will need Adobe Reader to view these documents.)
If you’re good enough, you can even unlock and download physical objects from the Killzone universe. “That’s impossible,” I hear you cry at your monitor, “You can’t to download physical objects through the Internet – let alone objects from a fictional universe.” Ah, but then you’ve obviously never witnessed the venerable art of papercraft:"
Stay tuned for more news about Killzone 2 and it's possibilities of interacting with Killzone.com