Update #2: These carrier settings will work with Beta 2 also. Also, Safari likes to attach a .zip extension to the ipcc, so either rename the downloaded file minus the extension or use Firefox/curl something else to download the updated carrier settings.
Update: Updated the MMS proxy settings, the previous version was using an old proxy. To update just re-download the carrier settings and apply an update once more.
After a little dicking around prompted by some stuff I noticed on twitter, I cobbled together this updated carrier bundle for O2 Ireland to enable USB/Bluetooth tethering for iPhone OS 3.0. This also enables the sending/recieving of MMS messages a new photo button will appear in Messages.app to send pictures as MMS messages.
Grab it here.
To install, option (alt) click update in iTunes, and select this updated IPCC.
If something terrible happens, you can grab a backup of the old one to restore here.