Safari 4 - open windows in Tabs

If you use Google's Apps ie docs and gmail then you'll know that you click the link at the top of the page to open a new browser window for eg calendar, currently by default Safari open each instance in a new window, not a tab.

To change the behaviour, quir Safari, and run

defaults write com.apple.Safari TargetedClicksCreateTabs -bool true

Restart Safari and now you get tabs by default.