I used the smart bro dongle before which you need to top-up 20 pesos for per hour internet usage, or you can opt for a monthly service of 675 pesos something. Its enough for video calling but really depends on the reception on the area where you from. A friend of mine was using the Sun says its also good. But really depends on the area.
I used to have one while I was in Phils. as part of my business and work.