Hi, I just jailbroke my iPhone 3GS, and I got mywi

I got mywi cuz I wanted to see if I could set up a wifi connectin so I could connect on my my iphone 3gs.. i am limited to 200meg a month which is NOTHING! i already went over and I wanted to find a way to make a wifi connection out of my mywi so that i could connect to my iphone my question is even though i am using the wifi will i still be using out of my 200meg or no? thx