There's a website you can visit to buy all your drugs - heroin, LSD - you name it. It's called Silk Road, and you have to be pretty tech savvy to even get to it. You can only access the URL through TOR, a network that keeps your info anonymous. And, the whole things works like Amazon.
"Silk Road cuts down on scams with a reputation-based trading system familiar to anyone who's used Amazon or eBay. The user Bloomingcolor appears to be an especially trusted vendor, specializing in psychedelics. One happy customer wrote on his profile: "Excellent quality. Packing, and communication. Arrived exactly as described." They gave the transaction five points out of five."
How do you buy what you want? With internet money! (Bitcoins.) That sounds about right.
Again, from Wired:
Bitcoins have been called a "crypto-currency," the online equivalent of a brown paper bag of cash. Bitcoins are a peer-to-peer currency, not issued by banks or governments, but created and regulated by a network of other bitcoin holders' computers. (The name "Bitcoin" is derived from the pioneering file-sharing technology Bittorrent.) They are purportedly untraceable and have been championed by cyberpunks, libertarians and anarchists who dream of a distributed digital economy outside the law, one where money flows across borders as free as bits.
To purchase something on Silk Road, you need first to buy some Bitcoins using a service like Mt. Gox Bitcoin Exchange. Then, create an account on Silk Road, deposit some bitcoins, and start buying drugs. One bitcoin is worth about $8.67, though the exchange rate fluctuates wildly every day. Right now you can buy an 1/8 ounce of pot on Silk Road for 7.63 Bitcoins. That's probably more than you would pay on the street, but most Silk Road users seem happy to pay a premium for convenience.