Should i buy iPod 4G or iPhone 3GS?

I know both of the devices are real different.
But i really am stuck.
The 3GS can be updated to the latest software.
The iPod 4, nothing to say.
Well the fact was that, we don't have Wi-Fi everywhere.
I live in bangladesh and 90% schools don't have Wi-Fi.
And i would really need to surf the web, every once in a while.
I was hoping for answers where iPod 4 had a few features which blows this off.
I don't already own a phone and won't be able to carry arround both pod and phone everywhere.
But i'm willing to buy thepod if there are more minblowing things up.

Added (1). In Bangladesh, you can't get into contracts with companies like AT&T.
you need factory unlocked ***.

At&T is giving the iPhone4 away for free if you activate a new account. Why would you get the 3GS if you can just get the 4.

I'm also Bangladeshi!
As far as I know Apple iPhone 3GS in
Bangladesh is (16 GB) 30000 or 40, 000 taka, right? The iphone 3gs is quite old model most of the latest apps will not run in the 3gs. I suggest you buy atleast iphone4 or iphone4s and if not then check out other smartphones it will be in that price range and also they will be recent model.
And ipod 4g is definitly better although its an ipod but it has the latest apps and facilities, and I would buy the ipod 4g instead of iphone 3gs, btw ipod 5g just released last month.