An electronic currency, which consists of cryptographic proofs-of-work, that can literally, verifiably, and securely transferred the over the internet from a buyer's bitcoin client (app, software) to a seller's without the aid of a mutually trusted third party (e.g., paypal or credit card bank, who traditionally collects a fee for this trust).
Western Union will charge you almost 5% to transfer $20,000 to India. They won't even let you do it in a single transfer since it is too big, and they'll hit you with an unfavorable exchange rate. Why don't you just send your vendor some bitcoin?
A crypto-currency allowing for anonymous transactions and using a decentralized architecture. Go Nanotube!
Nanotube was able to purchase many goods and services with Bitcoins, without the gubmint watching.