Your comments

I like it! A lot!

It's surprising Option wasn't used in place of Shift, seems more conventional for an alternate open mode. If Xcode and Textastic Mac use Cmd-Shift-O lets roll with that.

PS - is there a need for a UI button? It's a pretty power user feature. Is there a button for this on Textastic Mac?

PPS - who is printing their source code?! :)

This would really allow me to fly on Textastic too!

The WorkingCopy integration is awesome (Thank you!!!!). The only downside is how much it makes me wish for a quick open mechanism :)

I vote Cmd+P - Cmd+T has too much muscle memory for new tab.