What is this extra address on blockchain.info? I sent bitcoins for the first time to my friend. He has an address 1JkqP4qMvVpQApqyH4m9J4LBdqfFacMKSf 

I chose to send them through my wallet on Bitcoin-QT, but I was interested to check blockchain.info about the transaction as well. 

I see that blockchain.info shows that I sent bitcoins to another address as well! Can anyone explain why it shows that I sent bitcoins (about $30) to the address 1NTyaVoNrQYx2PA5ce7bVmqA6jfmSSkvxU on blockchain.info? I definitely did not send to that address...



This is my Bitcoin-QT client window. It shows the correct transaction amount.
This is because you did not have a coin that exactly matched the amount you wanted to send to your friend.  So bitcoin had to split a larger coin into 2 coins... 1 with the amount to send to your friend and the rest as "change" to send back to you.  The address you don't recognize is a new address that was created for the change, and it's in your wallet.