...BTW, the kerambit is not really an indiginous Philipino weapon and I have not really seen any actual FMA system use this weapon other than to adapt existing blade concepts to fit the weapons attributes...
Kun Tao, Silat, Spanish sword techniques, American boxing, and other arts all influenced many of the FMA systems, to include Albo Kali Silat. Some FMA systems have long incorporated Sangut (a Filipino "karambit" with a cord finger ring rather than a metal, integral ring) into their systems and others have adopted the more "Indonesian Style" karambit with the metal ring. Some use of existing reverse grip (pakal edge out) methodology is made when teaching karambit, but, in reality, the FMA elbow techniques, along with some reinforced punches, are often the best teachers of karambit motions. As in any weapon, the karambit can be defensive or offensive.
In many systems, the karambit is moved from reverse grip to extended forward grip and ripping draw cuts are conducted. In Albo Kali Silat, as in some other systems, there is limited use of the full spin of the karambit, while other systems do not spin the karambit, but only extend it.
Review the following link and scroll down to the article on the Sangut if you are interested in this Filipino weapon:
http://www.silkensteel.com/TnT_Arnis/2006/pdf/Vol3_No1.pdf
As for a primer on karambit use, may I suggest you go to this page on the Albo Kali Silat website, then follow the links to the webpages (and videos) that explain the basic, intermediate, and advanced karambit levels and mechanisms of use in Albo Kali Silat:
http://www.albokalisilat.org/beginner.html
(click the "Intermediate," "Advanced," etc. tabs under the video to navigate to the next page and video)
I hope this helped. Feel free to contact me with questions.