GetWeightedPrices       Bitcoincharts offers weighted prices for several currencies at http://api.bitcoincharts.com/v1/weighted_prices.json. You can use this to price goods and services in Bitcoins. This will yield much lower fluctuations than using a single market's latest price. Weighted prices are calculated for the last 24 hours, 7 days and 30 days. If there are no trades during an interval (like no trade within 24 hours) no value will be returned.
GetMarketData           You can access general market data at http://api.bitcoincharts.com/v1/markets.json. This will return an array with elements for each market.
GetHistoricTradeData    Trade data is available as CSV, delayed by approx. 15 minutes. It will return the 2000 most recent trades.