By default, Time Machine will start backing up as soon as you attach your designated Time Machine drive. This isn't an issue for desktops, but it can be for notebooks users who plug in their drives every day and then suffer an immediate slowdown as a result. There is also an issue with the preset one hour interval -- not everyone needs to back up that frequently. I prefer to do it once a day in the middle of the night.

The free program Lingon will allow you to change many aspects of Time Machine with ease (as well as many other aspects of Leopard). Here's how:

1. Download and Install Lingon.
2. In the right-hand column, access the System Daemon heading and highlight com.apple.backupd-auto.
3. In the main window, skip to section three, uncheck Run it every time a volume is mounted and check At a specific date:. Set days and time as you wish.
4. Save and Restart OS X.

Note that this previous hint doesn't require Lignon to be installed, but only alters the intervals between Time Machine backups.