I will soon be travelling to another country, where i imagine that any use of internet, such as receiving emails, will be charged onto my costs even though i have an unlimited data plan. Therefore, i would like to disable all internet functions, but still keep sms and phone calls, as i will not be charged for sms messages and i do not have to pick up the phone if i get a phone call.

Any idea how i can do this? I know i can disable all mobile network connections, but i really don't want to, just the email and internet...

Options > Mobile Network > Data Services = Off

or off when roaming...

What I did, and suggest you do, is call AT&T and have them remove your data plan before you leave, then just call and add it back in when you get back. I think you need to "opt out" of the plan, is what the guy in their blackberry division told me he did for me. This way, you don't get charged for any data use, and you actually save money on your plan, because you only pay a prorated portion.