One of the coolest pentatonic ideas I've seen came from a guy I used to take lessons from, where you're "overlaying" pentatonics over triads from within more complex chords.
For example, take a Fmaj7 chord. It's composed of the root, M3, 5, M7, or F A C E in the case of F. The "normal" way to solo over it using a pentatonic would be to play a F Major pentatonic - F, G, A, C, D. However, within that 4-note chord you can also create a second triad, an A minor over a root of F. So, an alternative to F major pentatonic that's still harmonically "inside" would be to play an A minor pentatonic, A, C, D, E, G. Essentially, it's the same scale, but with the F (the "root" of the chord) replaced with an E (the major 7th), but it's the same pentatonic box pattern. The M7 and the M2nd, straddling the missing root, help imply a major 9th tonality.
This same concept can be applied to any triad-based chord - simply play a major or minor pentatonic (whichever is appropriate) over the upper triad of the chord, or the upper triad of the chord you wish to imply over a simpler chord, and the pentatonic scale will help imply that sound.
I always thought this was a pretty cool sound - almost a bit arpeggio-y, with the wide intervals overlaid sparsely over the lower (missing) root.