+1
Although I'd suggest not using Alt+F4. IIRC that's used for virtual desktops in Linux. Personally I'd go for Ctrl+Q rather than Alt+F4 for four reasons: 1) Q for quit makes more sense than X, K, C, D, F4, E, S, or T; 2) It's in the corner of the keyboard (mostly); 3) It's next to W, and...