Windows 7: Need a program recommendation

Hi all, I am looking for a program that will allow me to, when I hold left mouse down, cause left mouse, or any other button to rapid fire. Playing Terraria and having to slam the hell out of my left mouse button to attack is getting old. Looking for a way to automate it when left click is held down.

Heh, found this annoying as well. Some have tried various hotkey macroing programs with varying results. I haven't heard of anyone actually mapping just left click into multiple left clicks though, because it makes doing anything other than swinging a weapon impossible.

AutoHotkey