Keyboard shortcuts for controlling mouse

[realisticphish]

Ok, I have a rather specific problem. It's not a complicated problem, but the internet seems helpless to suggest anything.

I play Minecraft a LOT, and if you've ever played, you need to press and hold the left mouse button to do anything. Needless to say, after hours and hours, my finger aches from pushing the button. What I want is a toggle key that will turn on the left mouse click input, which i can hit again to turn it off. Or, hell, just a key to press, even if not a toggle, would help.

Yes, I know about Mouse keys. But, frankly, it blows chunks. When you're using any of the buttons, it completely cuts mouse control. So I have to use Mouse Key's directional keys, and it moves glacially slow even at the fastest speed. Plus, option key 5 times to turn it on? Wtf?

I would love to use something like AutoHotKey, from what I've read on the Minecraft forums. But there's no mac version.