Ease up Jh32uk2. You are acting way too elitist for this type of forum. A mature person would take into consideration the type of forum gamespot/faq and respond accordingly. You have not responded accordingly. I would have agreed with you in perhaps a different location, but not here at gamespot. The fact you felt the need to respond without telling him how to do it makes me wonder if you knew yourself. Maybe its just me, but the mature answer would have been to give an answer but recommend using the search feature next time.
OP I personally am not a big fan of Fraps, though mainly because I have never paid to use the full version (nor pirated it). There however many free alternatives to the software, though I am not sure which ones tell you the fps as well. Usually games include their own fps command, given that batman runs on the unreal 3 engine... it should work as UT3. (press f10 for console then type stat fps). I havent tested that method with Batman though. I also recommend checking out this site: http://www.anewmorning.com/2009/01/06/5-free-alternatives-to-fraps/