I've found that incorporating the flat 5, major 3rd or 6th into the pentatonic scale can really open up your legato possibilities.
Obviously, there's a drastic tonal difference between these notes, but as they are being added to the minor pentatonic, tonally you can get away with it, especially when playing at speed.
It creates a very chaotic, manic-sounding effect, which is right up my alley.
Players often will combine lots of different modes, etc., to their soloing. I do the same but with a different approach; I base everything around the pentatonic, so instead of playing modes, I simply add the notes to the pentatonic. This way, I always have that rock base behind the sound.
The stretches are the main challenge here. If they're too much for you, simply move the idea up the neck into a different key where the pattern is more comfortable. Then you can slowly start to move it back down.
Once you start to work through the legato pattern, you'll notice the pattern repeats, so the motivation should be that you'll be able to adapt this technique to create your own runs in any position.
This sound is captured purely from blues-based scales. It is created by combining two patterns of the pentatonic, rather than playing the scale in the traditional two-note-per-string form.
The great thing is you can adapt this idea into many different genres. You can give it a different feel or use it with a cleaner sound, etc. It doesn’t have to be played at a million mph to sound great; it can be used in many different ways. This is just an example of how far you can take the idea.
Australia's Glenn Proudfoot has played and toured with major signed bands and artists in Europe and Australia, including progressive rockers Prazsky Vyber. Glenn released his first instrumental solo album, Lick Em, in 2010. It's available on iTunes and at glennproudfoot.com. His brand-new instrumental album — Ineffable— is out now and is available through glennproudfoot.com and iTunes.