The Flatted Fifth Blues Scale
Adding the flatted fifth to the pentatonic minor scale produces the famous blues scale. This is a really awesome scale for learning to solo - so awesome that we really don't need to go anywhere else to create some great music!
Here's a diagram of what it looks like on the fretboard:

The numbers on the dots indicate the musical distance from the root note, R.
Is this scale familiar to you? On a scale of 1 to 5 how would you rate your confidence in using it to create guitar solos? Let me know in the comments below!