Watch the Use That 9th! online guitar lesson by Angus Clark from 50 Radio Rock Licks You MUST Know
By simply adding one note to the pentatonic scale you open up a world of possibilities. This hammer-on pull-off combo on the top string gets you some of that Hendrix sound in a quick little turn. Interestingly, I think that the degreee to which this element is signature to Jimi's sound was revealed to me only once I heard Stevie Ray Vaughan employ it in a different context.