This shirt was available for one day only at http://shirt.woot.com about a week ago.
The wording is easily recognizable from Jack's speech to the fuselage survivors in Season 1 of LOST.
I will admit that I didn't understand the crown reference until it was explained to me:
The crown image was used with slogans to boost morale in the UK during WWII.
"Keep Calm and Carry On"
Olly Moss, one of my favorite print artists from the LOST Underground Art Project,
also created his own take on the slogan:
I tend to live in the Olly Moss camp.