Every time I connect my iPhone to the computer, iTunes would start backing it up. And it’s slooow – really slow – at least half an hour of waiting.
There’s a fix for this, which I found on Zerologic: disable automatic iTunes backup, and only allow manual backups for it.

Here’s how to do it:

1. – Quit iTunes.
2. – Open Terminal.app
3. – Copy and paste this in, then hit return:
defaults write com.apple.iTunes AutomaticDeviceBackupsDisabled -bool true

4. – Copy and paste this in, then hit return:
defaults write com.apple.iTunes DeviceBackupsDisabled -bool false

5. – Open iTunes
6. – Plug in your iPhone (2.0 or 3G) and sync.

Now it finally looks more like in the good old days of the 1.1.4 firmware. Almost instantaneous sync. Hurray!