Yes. All iPhones are capable of standard 3G connectivity (on most bands) except for the original iPhone (launched 2007, no longer commercially sold).
Yes, you can use your iPhone 3G(S) to access the Internet if you have an available WiFi connection.
if you are using something that requires it then yes it does use internet
The iPhone has an internet browser called Safari. In theory, if you have access to a WiFi connection, you can connect to the internet. Also, you can connect to the internet through a networks 3G connection.
It could be an issue with your internet connection. Try using a different connection or on 3G.
The 3G has 3G connection, and I believe it is a little faster too.
As long as you have a connection to a network(Edge, 3G, Wi-Fi) and that network is connected to the internet, yes, it is always online.
Yes, the iPhone 3G has Wi Fi.
3G is the service for things like the internet... just like in the old iphone there is Edge.
No. It can use your 3g
You get faster internet then the original iPhone.
either will work. If you are having your email pushed more than 1 an hour, it will use substantial data on your phone.
so that where wifi is unavailable, u can use 3g network