I’ve jailbroken my iPhone 3G, extracted and modified the bundle included, to enable tethering, set up MMS properly (full resolution photos anyone?) and properly configuring Group SMS.

Previously if you attempted to send a SMS message to a group of people, it would instead be sent as a MMS, at MMS rates. Not good. [This carrier update allows you to send multiple messages to groups as SMSs, not as MMSs – Benny]

This new bundle also conforms to the official bundles avaliable for iPhone OS 3 (unneeded/redundant settings have been removed, like EnableMMSCEditing).

All data (iPhone data and tethering) goes through the telstra.iph APN, and MMS goes through telstra.mms.

You can find the carrier bundle here: Telstra_au.ipcc.

via iPhone Carrier Bundles Update | Selling Expectations.

Beau then goes on to handle that pesky no-manual-carrier update issue:

Enabling custom carrier file uploading in iTunes 8.2:

For OS X users, paste or type the following into Terminal, and then restart iTunes:
defaults write com.apple.iTunes carrier-testing -bool TRUE

For Windows users, please paste these into ‘Run’ (Press WinKey + R while on the desktop:
32bit –
"C:\Program Files\iTunes\iTunes.exe" /setPrefInt carrier-testing 1

64bit –
"C:\Program Files (x86)\iTunes\iTunes.exe" /setPrefInt carrier-testing 1