To stop Mac OSX from creating .DS_Store files to network drives run the following command.
To jailbreak the latest firmware for the iphone 3G just update your firmware using iTunes then download blackra1n and run it.
Once completed run blackra1n on your iPhone and install your preferred app installer.
It’s pretty simple. Please note however that noone has managed to unlock these recent firmwares so if you require a software unlock then either wait or follow one of the guides on the net for building a custom firmware without the baseband update.
One issue discovered is if you use DiskAid or iPhoneExplorer it appears blackra1n stops you accessing the root of the filesystem. The current fix if you require this access can be found here. Hopefully a newer version of blackra1n is released that takes care of this issue soon. Alternatively download afc2add from cydia.