While it is risky for sellers to offer this option, three services now will allow you to buy bitcoins with your credit card. However, that does not mean it is entirely risk free, if you are from Asia or Africa your funds may be frozen by credit card payment processors for further inspection due to the large amounts of fraud that come from those continents.
Note: If you only want to take advantage of Bitcoin's price volatility You can trade CFDs on Bitcoin via a credit card on sites like AvaTrade or Plus500. When trading online your capital may be at risk. Trading CFDs is suitable for more experienced traders.
VirWox (Paypal)
The Virtual World Exchange also known as VirWox allows you to buy SLL (Second life Lindens) with all major credit cards which you can then exchange to Bitcoins on VirWox itself. The process is done through the use of Paypal, so every credit card which Paypal accepts is eligible to be used in this process.
Western Union
US customers can use Western Union to buy Bitcoins with their credit cards. Unlike Paypal, Western Union will allow you to buy Bitcoins through services such asCoinMama.
Coin.MX
Coin.MX - Crypto Money Exchange - if you are from USA, you can use your credit card to fund your coin.mx account and buy BTC or LTC currencies. Requires verification of identity by posting a video to the site.
BTC-Dealer
BTC-Dealer is a fixed rate exchange for credit cards. Payment processor is LiqPay. Funds may be frozen for several days if transaction is suspicious. Some transactions are rejected by the payment processor.
Buy Bitcoin With Credit Card
Buy Bitcoin With Credit Card allows you to buy loaded paper wallets using a credit card, with the option of (upon shipping) having the bitcoin that would have been loaded onto the wallet sent to your bitcoin address instead.
Bitcoin By Credit Card
Coming ?/?/13*** BBCC allows you to buy bitcoins by using a credit card. Launch date is unknown.
Mt. Gox
Mt. Gox indirectly allows you to buy bitcoins by buying Linden Dollars with your credit cards, and then converting them to bitcoins. Unfortunately this process could take up to a full week, however they are very reliable.
BitcoinExchange.io
BitcoinExchange.io allows you to purchase up to $20 USD worth of bitcoins at a time with a credit card.