As I'm sure people constantly snicker about, your average user, be they Windows or Mac users, will know nothing about anything technical.
Today I'm attempting to breach that gap, for the Mac users at least, and I'm handing out an open source Minecraft.jar extractor/compressor that only requires two clicks and the following of the instructions that came with the mods being installed. In case the user installs incompatible mods it also makes a backup as bin/minecraft_vanilla.jar.
If you use mods for playing on a server but not for single player then you can choose what jar to run every time you run the app.
Credit for helping with Growl support goes to Qatalife.
Please leave a comment of what features you think it needs and any bugs you find.
It asks for Growl's location at the end if Growl isn't installed. It doesn't pop a notification at the end if Growl is installed.
I uninstalled Growl to see if I had fixed that and for some reason it always prompts, no matter how I write the if statements, it seems to be a bug with AppleScripts and not just my script. Version 1.2 of Growl is still free and works on Lion perfectly.