Sahi Al Bukhari 7.494.2:
Narrated Abu 'Amir or Abu Malik Al−Ash`ari: that he heard the Prophet saying, "From among my followers there will be some people who will consider illegal sexual intercourse, the wearing of silk, the drinking of alcoholic drinks and the use of musical instruments, as lawful. And there will be some people who will stay near the side of a mountain and in the evening their shepherd will come to them with their sheep and ask them for something, but they will say to him, 'Return to us tomorrow.' Allah will destroy them during the night and will let the mountain fall on them, and He will transform the rest of them into monkeys and pigs and they will remain so till the Day of Resurrection."

Don't yawn if you are near a Muslim
Sahi Al Bukhari 8.242:
Narrated Abu Huraira: The Prophet said, "Allah likes sneezing and dislikes yawning, so if someone sneezes and then praises Allah, then it is obligatory on every Muslim who heard him, to say: May Allah be merciful to you (Yar−hamuka−l−lah). But as regards yawning, it is from Satan, so one must try one's best to stop it, if one says 'Ha' when yawning, Satan will laugh at him."

Chapter 2: IT IS PROHIBITED TO PLAY CHESS
Bk 28, Number 5612:
Buraida reported on the authority of his father that Allah's Apostle (may peace be upon him) said: He who played chess is like one who dyed his hand with the flesh and blood of swine.