Tonight I made an ear training video for guitarists. It's meant to help learn the sounds of the open chords on a guitar (a chord with at least one open string left ringing.) Developing your ear in this way enables you to be able to learn songs by ear and be a better all around musician.
The video works like this: First you'll hear a guitar chord and you'll have a chance to make a guess at what it is before the chord plays for a second time with the correct chord shown on the screen (with the chord fingering in tab format.)
You've done well if you pick the correct chord family (the video includes at least one of each of the following types of chords: major, minor, dominant 7, major 7, suspended 4th.) If you also pick the exact right chord (like C7 instead of just "that's a 7th chord") then give yourself bonus points!
There are 24 questions/answers in this video which should be enough that you can use it multiple times before you begin to memorize the answers. I do plan on making more of these videos though because eventually - if this one video is used too many times you'll probably begin to know the answers based on memory rather than your ear.