Very Low Effort:
http://cur.lv/98t2   -   Tweet ads on Twitter for BTC
http://cur.lv/98u3   -   Get ads to put on your website/blog

Gambling:
http://cur.lv/8g61   -   Simple minefield game, win up to 22.5x your bet
http://cur.lv/96ml   -   Simple darts game; random, but high winning chances

Free Periodically:
http://cur.lv/96pt   -   Free daily BTC game (Pays varying amounts)
http://cur.lv/98tk   -   Free hourly BTC
http://cur.lv/98tl   -   Free daily BTC (Hourly if you sign up for an account; Can also complete simple offers for more BTC)