I have a iphone 3G on tmobile MMS activated and i was wondering if there is a way to get the yahoo messenger app to work. I do not have a web2go plan or any data plan. On my old phone i would go to IM and i would have options ot sign into yahoo,aim,MSN and others, and it would work but know i dont know how to do it on the iphone.

(old phone:samsung behold)