# Enable tap to click. (Don't have to press down on the trackpad -- just tap it.)
defaults write com.apple.driver.AppleBluetoothMultitouch.trackpad Clicking -bool true
defaults write com.apple.AppleMultitouchTrackpad Clicking -bool true
# Enable tap to click for the login screen. (May or may not work in Mavericks.)
defaults -currentHost write NSGlobalDomain com.apple.mouse.tapBehavior -int 1
defaults write NSGlobalDomain com.apple.mouse.tapBehavior -int 1
# Enable 3-finger drag. (Moving with 3 fingers in any window "chrome" moves the window.)
defaults write com.apple.driver.AppleBluetoothMultitouch.trackpad TrackpadThreeFingerDrag -bool true
defaults write com.apple.AppleMultitouchTrackpad TrackpadThreeFingerDrag -bool true