[sevensor]

> I try to do this quietly

If you hold a mobile phone to your ear, nobody will give you a second look.

[iagooar]

Unless you get a real call while doing so.

[jacquesm]

"Please hold while I get the other line"

(what should really worry you is if you hear 'ok.')

[jonsterling]

Just make sure your phone is charged, since you'll look like a real douche if there's an emergency and you need to call police/ambulance with your dead phone that you've just been talking on...