Another click, the voice states you have reached the head of the queue, your call will be answered as soon as the next operator becomes available.

BBC: THE UNANSWERED CALL

An easy-to-navigate menu lets you queue units or call in reinforcements from anywhere on the map, and building your bases and commanding your soldiers is as easy as pointing and clicking the mouse (you'll need to use a few keyboard commands, as well).

CNN: Review: Command & Conquer: Red Alert 2

Unison said that once calls are transferred to the NHS Direct Wales queue they effectively take priority over other calls waiting for a call back.

BBC: NHS Direct Wales 'turned off' for 999 calls, Unison claims

This margin depends on the size and speed of an aircraft, and re-ordering the queue can minimise the delay before all the planes get into the air (mathematicians call this the departure problem).

ECONOMIST: Algorithms

Others complained to BBC News Online that they spent more than half an hour in a queue for the technical help line of the Genie Wap service - a premium rate call costing 50p a minute when accessed on a normal telephone landline.

BBC: BT in Wap phone trouble