[tehwalrus]

Worrying about whether you're doing it right or wrong is much more of a failure than using an unfocussed screen and gentle music/sounds.

If you're good, you should be able to successfully meditate whatever is going on around you. I can (just about) do it on the tube (subway) during my commute.

[jimmaswell]

Right, you're supposed to be able to do it whatever's going on, so it's bad to use anything as a crutch.