htc aria or iPhone 4....?

[Sheri]

i have AT&T and my upgrade is ready, i have had a iPhone for literally 3 years now and im going to be honest...its getting old right now i have the 3gs. I like it but now i need to make a choice move on the iphone 4 or something new. no matter what i need to stay with AT&T and the aria looks like a cool phone. i want to see what this andorid stuffs all about. my friend as the samsung fasinate for verizon and its actually really nice. im getting sick of apple and there lame restrictions. i cant really customize anything and android seems really cool about that. i have a few other questions, like on the android market, when i buy apps what dose that chrage my credit card just like the app store on the iphone? just give me your opion please