These may include coding hacks or general hacks using some software. The criteria being they must be useful and easy to learn within a short span of time.

Answer:

Here's an oldie but a goodie for Windows machines. It will let you hide a file inside another file. So in other words you can hide a zip file inside an image.

Open a CMD shell (or powershell)
cd to a folder that contains a .gif, jpg etc and a .zip file
Run the following command: copy /b MyPic.gif+MyArchive.zip MyZipPic.gif
The resulting file can be opened by an archive extraction app like Winrar or whatever, and also in an image viewer. It will appear as an image in the OS however so the zip file is hidden well. It should work for other file types too.

Here's another kind of cool trick that has no practical use whatsoever, but is cool to show your friends. It will show you Terminal Star Wars:

You need telnet. It will be available by default on OS X and other 'nix machines. On Windows, you generally have to go to the Control Panel > Add Remove Features and add the Telnet option
Open a terminal on nix, or CMD/Powershell on Windows.
Run the following command: telnet towel.blinkenlights.nl
Enjoy the terminal version of Star Wars. It goes on forever. Someone put a hell of a lot of time into it.

Heres one more for an iPhone. It will show you numbers instead of bars which is much more accurate. The lower the number, the better the signal. Basically anything under 105 or so is a decent signal. 90 would be great.

Go to the phone app and dial this number: *3001#12345#*
That will bring you to the field test. Hold the power button down until the "Slide to power off" control appears but don't slide it.
Hold the Home button down until the slider and field test goes away. You should see numbers instead of bars in the upper left.
Just do it again if you want to change back. EDIT - Per Luis Villa's comments, apparently doing it again doesn't always change it back for everyone. If that's the case, try following these instructions:
'Go to the phone app and dial this number: *3001#12345#* once on field test. press "Back to phone" on the upper left corner.'

There are some other cool things you can do in that field test app but I'll leave those for someone else.

Source: https://www.quora.com/What-are-some-...-in-10-minutes