Thank you Chris and Tom, for your responses,
Here is my plist. I put this in /Library/LaunchDaemons. What do you think? --Thanks, Allen
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "
http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
<dict>
        <key>KeepAlive</key>
        <true/>
        <key>Label</key>
        <string>stunnel_startup</string>
        <key>ProgramArguments</key>
        <array>
                <string>/opt/local/bin/stunnel</string>
        </array>
        <key>RunAtLoad</key>
        <true/>
</dict>
</plist>