<key>LSMinimumSystemVersion</key> <string>10.6.0</string> <key>LSMinimumSystemVersionByArchitecture</key> <dict> <key>x86_64</key> <string>10.6</string> </dict>
10.6 is much nicer than 10.5 on a bunch of levels. It's slightly annoying now, but will pay off in the future.
<key>LSMinimumSystemVersion</key> <string>10.6.0</string> <key>LSMinimumSystemVersionByArchitecture</key> <dict> <key>x86_64</key> <string>10.6</string> </dict>