Some nifty commands that I use often on other platforms but I miss on Mac. After googling around, I found the Mac equivalents.

Showing the desktop: Cmd+Option and then click on desktop.

Taking snapshot:

• Command-Shift-3: Take a screenshot of the screen, and save it as a file on the desktop
• Command-Shift-4, then select an area: Take a screenshot of an area and save it as a file on the desktop
• Command-Shift-4, then space, then click a window: Take a screenshot of a window and save it as a file on the desktop
• Command-Control-Shift-3: Take a screenshot of the screen, and save it to the clipboard
• Command-Control-Shift-4, then select an area: Take a screenshot of an area and save it to the clipboard
• Command-Control-Shift-4, then space, then click a window: Take a screenshot of a window and save it to the clipboard 

Pre compiled binary for the famous wget Linux util:

https://techtach.s3.amazonaws.com/files/wget

I will keep this list updated.