Berry 9000.

Tel$tra Australia.

Unlocked.

I have a bog standard data plan with Tel$tra that allows web browsing etc.

However when I try to activate GMail application (downloaded from Google) I get an error message "This proggy requires a working data connection yada yada".

Confused here (as usual!). I already have a data plan!

Wirelessly posted (RIM BlackBerry 8300 Curve)

BlackBerry Internet Service (BIS)
Most consumers that have a BlackBerry device for personal use (such as myself) utilize a BIS, which will give you unlimited data and e-mail, as well as call-rates based on the service plan that your BIS is "attached" to...

For example, I have a Telstra Business Cap Plan with a BIS "attached" to it, offering me "$x" of telephone calls and messaging, plus unlimited sending/receiving of e-mail messages and unlimited data.

At the time of writing, Telstra's BIS service plans are $29.95 if you agree to a 24-month contract, or $49.95 if you want a month-to-month (non-contract), "casual" BIS... You'll also need to select an "eligible" service plan for your telephone calls and messaging (excluding e-mail, which is covered under your BIS) which is most, but not all, service plans.

Make sure that you access ALL Telstra content (BigPond Mobile, Foxtel Mobile, etc...) using the "Telstra Business Portal" (this browser will be "pushed" to your device when you setup your BIS) and ALL non-Telstra content (third-party Web sites, etc...) using your "Browser" - failure to do this WILL result in additional charges on your account!

Finally, remove your Browser Pack (you don't need it if you have a BIS, because this gives you unlimited e-mail and data; Telstra should do this for you when you setup your BIS...)), and make sure that your Access Point settings are BLANK and SWITCHED-OFF (on the BlackBerry Bold 9000 and most newer devices, these settings can be found in Options-->Advanced Options-->TCP/IP) - this is a BIG, BIG point because if the Access Point settings are in-place and/or activated, you will almost certainly end-up with a VERY, VERY big bill for data!

I'm a Telstra customer and spent almost ten years working in the Australian telecommunications industry (mostly Telstra, but also a few other companies), until I recently when joined the Australian Army - feel free to send me a "PIN message" or contact me using BlackBerry Messenger if you have any other questions:
pin:21445DCA

If you have trouble getting your BIS setup and therefore can't utilize the BlackBerry-specific PIN messages or BlackBerry Messenger, send me a private message here, where I will be able to provide you with my e-mail address....

Thanks for the offer. Do you mind if I pass on to the IT guy at work - a bit beyond me!

Should I also cancel the Tel$tra data plan that I am on now?

Cancel your old data plan as a BlackBerry Data Plan completely supersedes it.