There's a very old method to buy btc via paypal but it has high fees and I think the minimum amount you must buy is 0.01 or 0.02 btc. Virwox offers btc for paypal exchange with SLL. Not many use it though due to high fees and rates. Depositing $50 you might walk away with $40 of btc.
I can comfirm, I had my first bits of BTC that way. Good to test and play with few but definitely not for big amount.