For want of a meta, the war was lost...

[sawyl]

I've finally worked out how to map alt to meta in the OS X terminal emulator. It's simply a matter of picking File->Window Settings... and then, in the Terminal Inspector dialogue, setting an option the keyboard section. If only I'd taken the trouble to spend thirty seconds sorting this out when I first set up my mac, I wouldn't have spent the last three years feeling mildly frustrated at having to use the escape key.