That contracts based on the price of some commodity or asset have been around for about as long as mankind has been trading indicates that they are pretty useful.

ECONOMIST: Economies need derivatives, but reform is justified

After all, the US has been for a long time a useful military protector, a powerful economic model as well as an enduring normative power to most of them.

FORBES: Obama And Romney: And The Loser Is?

"We are in this for the long term and have experience with multiple generations, so the name should be useful as a symbol of continuity, " says David Rockefeller Jr.

FORBES: Old money chasing new

ETFs can be useful for short-term plays, but many are not the best choice as long-term plays.

FORBES: Why Leveraged ETFs Don't Always Boost Returns

However useful as a pressure tactic, actually indicting Lewinsky for perjury would have guaranteed a long trial and an even longer delay in the prosecutor's pursuit of his real targets.

CNN: Tick, Tock, Tick... ...Talk

Independent fact checkers have said that offshore drilling will have no short-term, and little long-term, impact on gas prices, but McCain has said it would be useful as a symbolic gesture to signal U.S. resolve not to be dependent on foreign oil.

CNN: Economy takes center stage in bruising political ads

Our research also revealed that one in two mobile media users is happy to receive advertising messages on their mobile phone, as long as those adverts are relevant and bring benefits to the end user, for example in the form of coupons, useful alerts, or location challenges.

CNN: Will mobile kill digital advertising?