Category

BTCvert

Bitcoin Prices and Exchange Rates updated automatically.
http://btcvert.com/

Chain

Block Chain API for Developers
https://chain.com/

Cryptothrift

Bitcoin and Litecoin marketplace and auction site
https://cryptothrift.com/

Jobs4Bitcoins on reddit

A place to offer your talents and skills in exchange for the fastest growing currency in the world.
http://www.reddit.com/r/Jobs4Bitcoins

Satoshi Nakamoto Institute

I've been working on a new electronic cash system that's fully peer-to-peer, with no trusted third party. - Satoshi Nakamoto, 2008
http://nakamotoinstitute.org/

Map of Coins

Visualized history of cryptocurrencies from bitcoin launch up to present day: over 200 altcoins on one map.
http://mapofcoins.com/

MintPal

Fast, Efficient and Secure Cryptocurrency Exchange Featuring Bitcoin
https://www.mintpal.com/

Crypto Rush

Exchange InfiniteCoin for other cryptocurrencies
https://www.cryptorush.in/