How to Disable the Lion App Resume Feature in Every App but Safari
If you're like me, you find Lion's feature that restores documents in apps after you relaunch them to be more of a hindrance than a help. Well, like most other Lion features that people hate, you can turn it off. Just go to System Preferences > General, and disable the checkbox next to "Restore windows when quitting and re-opening apps" as indicated in the screenshot below.
Now it may not appear to be turned off at first because some apps don't pick up on it until after a relaunch or two, but this should do the trick.
Of course I actually want this feature for a select few apps. In fact, Safari is the only one I can think of right now. To re-enable this feature in Safari after turning it off for everything else, enter this command in the Terminal:
defaults write com.apple.Safari NSQuitAlwaysKeepsWindows -bool true