Say I want to store one Bitcoin in a new address and then not think about it for the next 10 years. How can I 'lock away' 1 BTC?
Create a paper wallet, preferably an encrypted paper wallet with a password which you cannot possibly forget.
Print out a bunch of copies of the wallet and stash in several safe places. Home, Car, Truck, Office at work, parent's house, etc.
Send your BTC to the address on the wallet.
When you wish to retrieve the BTC, use the import private key function in the bitcoin client, and specify the private key on the wallet.
It's worth making a few disposable paper wallets and testing them out with 0.000001 BTC or similar to see how they work, before you try for real.