Here's here. According to 9to2Mac, Apple has finally enabled a two-step verification for iCloud. I've been using this for Google accounts and it's seemless. I know I'll feel mucho better about iCloud now.
Right now, Apple's website for Apple ID is up but there's all these weird strings. My advice is to wait a few hours until the dust settles before sign up for it. But do sign up for it.
The way it works is that you type in your ID and password as you normally do. You already do this.
Then Apple will send to your iPhone, iPod touch, or iPad a second code that you'll have to enter to gain access to your account. Enter that access code and you're in. If someone else tries to log in with your credentials, even if they have the password, without the access code, they're still locked out.