A new update to Final Fantasy XIII-2 allows you to share your achievements in-game with you friends online via Facebook. If you're feeling especially brave and don't mind taking flak from people who hate it despite never having played it, this is absolutely the best way to prove what a badass you are.
Simply turning on SNS messaging within the options will give you the opportunity to share your capture of monsters, your collection of rare items and rare events with all the people on Facebook. It's supposedly a little buggy, and some details presented in the potential post can be incorrect, so expect another patch in the not too distant future.
To make use of the Final Fantasy XIII-2 Facebook system you'll need to download patch 1.03. The game came out today in Europe and, despite rumours to the contrary, will be available for purchase from GAME and Gamestation stores.