Can I upgrade to iPhone 4?

[ToastyToci]

Can I upgrade to iPhone 4 with no additional cost? If not, how much would that cost be?

I have an iPhone 3GS, and I purchased that in December 2009. Will I be able to upgrade for free? If not, how much will it cost? Thank you...please let me know.

 

[cowsrus]

Call *639# on your iPhone and then check your text messages, it will tell you what you can do