http://www.bitvisitor.com/?ref=17yLjnY8zyANY7uexaLR7oai5EDA48LdL9

Visit that site, input your bitcoin address, submit, enter captcha and then wait five minutes. You can minimize the window while you wait. Come back, hit next, enter another captcha and wait again. You won't get rich but you will make a few uBTC.