Now what to do? Spill the beans and unleash 150 autograph hunters on a shy actor, or say nothing and deny fans a one-off chance to touch Hollywood?
After an "economic fire" had wiped out Detroit's property values, there was a one-off chance to buy lots of land and redesign the whole stretch from scratch.
For Chad it was a one-off chance - its reserves look likely to last for only 30 years - at rapid development.
Given a one-off chance to tell the world what they think of how they are governed they have screamed a piercing cry of alienation and desperation.
Now the bank and Mr Hall both think that Microsoft's model may be a better alternative to options than restricted stock.Microsoft offered its employees a one-off chance to sell their options to J.P. Morgan.
If a country grabs this one-off chance for productivity gains and investment, economic growth can jump by as much as a third.Less is moreHowever, the fall in fertility is already advanced in most of the world.
The government was beginning to deregulate the business, and Mr Lay spotted a one-off chance to profit handsomely by creating innovative instruments for the nascent spot and forward markets in energy products.
No building for orchestral music has ever been made like that in the UK (Miami's Frank Gehry-designed NeWorldld Center is one of the very few precedents), and in my view, it's a one-off chance that must not be missed.
They represent a one-off chance to scribble months or years of learning onto paper, and can make or break future career prospects.
"It is a one-off chance to do something which probably I don't think any of these lads have done before, which is playing in a World Cup semi-final," added Edwards.
The ticketing for games between teams of vastly different stature can be controversial, whether it's clubs with huge followings squeezing into small grounds or lower-league fans clamouring for one-off chances to visit prestigious venues.
