How to disable Preview from opening up the last couple items viewed? osx lion
To stop only Preview from doing this open up Terminal.app and enter:

defaults write com.apple.Preview NSQuitAlwaysKeepsWindows -bool false


To re-enable this at any time enter:

defaults write com.apple.Preview NSQuitAlwaysKeepsWindows -bool true


If you want to turn off the resume-on-load feature for all applications you can go to System Preferences -> General and at the bottom of the screen uncheck the option Restore windows when quitting and re-opening apps to prevent any application from doing this.