Iphone switching to T-Mobile questions! Help!

[thomieg95]

If I was getting a Iphone, and putting it on T-Mobile, would I be able to put it on my family's plan or would I need a special plan by myself? Second, my phone right now has unlimited texts and unlimited minutes, but no internet, but my mom told me that if I get the same phone she has, Google Andriod G1, I wouldn't have to pay anything more than what I am now since were on the same plan, is that true? Because if it is true, wouldn't that mean I can get a Iphone and have it be just like a G1? She does have unlimited everything with internet on her phone and she pays $65 a month (just for her phone, not including the whole family package).