There are also free bitcoin faucets on the internet that give out small rewards for doing tasks (bitvisitor.com) or just visiting their site. Most of these are on a timer of 30m to 1h with a few being on 24h.
A nice little place to visit is coinreaper.com as it has an integrated tracker to see how long you have to wait before you're allowed to enter your address again for a new reward.

But your best bets to get bitcoins are still mining or buying them. The faucet rewards are tiny and you need to spend a lot of time every day to get anything significant.