I always seem to find really cool commands when I need them, use them and get what I want done then I seem to forget where I got them or how I found them. To combat this I have started a command page. I will post all the commands that I find, what they do, etc on that page. This way there is a common place to find really useful stuff and I wont forget them forever.
Feel free to comment with your commands that you use and find useful. Ill add them to the list.