Apple iPhone 3GS

if you have the iphone $30 data plan with at&t, you have the "iphone plan." in short that means if you pay at&t $30 a month for you iphone data plan, then you have visualvoicemail included. it should run you through a setup process when you hit the "voicemail" icon under "phone." if it doesnt after a fews days then you should call at&t and maybe they need to reset your data plan.

I understand what you are say but I am on $15 data plan and don't want to pay for the iPhone plan. I want to know if I can still get the Visual voicemail?

Then no u wouldn't be able to use visual voicemail.

Don't be surprised if one month you get a bill for data overages and it's pretty pricey.