A call option is a contract, allowing you to buy the asset at a specific price at a specific time. I'll put parenthesis to make it easier to understand... IE: I'll sell you a (contract to buy 10 BTC for $30 each on April 30, 2013) for $300.

So today, you can buy the contract from me. In April 30, if BTC remains high in price, you can execute the contract and buy 10 BTC @ $30. If BTC crashes in price, the contract is worthless, and you can instead buy BTC from the market. You make a profit if on April 30, the price of BTC is $60 or higher.

The opposite is true for put options. You buy put options to sell BTC on the market at a particular price at a particular time.

Here's the kicker: options are bought and sold on the open market. IE: The futures market. So the spot price of $300 for this contract will go up / down based on what speculators believe the price of BTC will be in 30 days. (The terms of the contract don't change. Only the cost of the contract changes)

For businessmen who primarily work in USD, getting a spot price of BTC way off in the future will help solidify his business.

The underlying asset may be volatile, but futures allow the businessman to guarantee a price on the BTC <--> USD exchange.