Three is a small number that promises a short story. So, I'll dive right in.

1. Check the weather anywhere quickly and easily

You don't even need an app for it!

I can't believe I didn't know this before today, but Spotlight actually has integrated weather support. So, simply:

1. Cmd+Space to bring up Spotlight
2. Type in "weather New York" or wherever you are and enter to see expanded results.

2. Capture un-selectable text anywhere on your display

With the free handy little app OwlOCR, this daily need becomes a breeze.

1. Press Cmd+F1 to start the area selection.
2. Select the area on-screen.
3. Near instantaneously the text is in your clipboard to paste into any app or purpose.

3. Change display resolutions without diving into the settings

EasyRes is a free app that makes this super-easy from your menubar - toggling both the internal display and external displays.

Hope these help, please share your daily productivity shortcuts in the comments!