Hey,
I'm definitely an RB fan and I've checked out his videos and seen him live a few times - he's pretty amazing at groovinmg and soloing at some serious speeds - and I've also been fascinated by his picking techniques. What I think he's doing is a lot of muting, and he also does a similar thing to Wooten, in that he emphasises the downbeat by bouncing his RH up and down, very subtley, so he gets a really synchopated, percussive groove going. He also does a lot of string skipping, playing lower notes in the octave as a bass line, with accents on the off-beats on the higher notes in the ovtave. The main thing to making all this sound so groovy is playing it in a totally relaxed way, and knowing exactly when and where to place the ghost notes witout it sounding overly busy.
Now the thing about his speed playing is that he uses legato - or slurring - to make the runs of notes he plays slide together. While this technique is potentially easeir than picking each note individually with alternate finger picks, the thing with playing legato at the speed Bona does it is that you have to hit certain notes in the line that will enable you to keep the hammer-on-pull-off thing going for the whole phrase - and that is very hard, because you have to vary this according to what you want to play. It seems easy at first with just scales or even arppeggios, but really controlling it and shaping phrases with it is really challenging - my advice is go slow at first.
Lastly I have seen him use three fingers a la Sheehan, to get up some fast 32nd note things - and that's about it. There are a couple of DVDs with him on - his new one called 'African Tale' is worth a look, but doesn't feature that much of his solo playing, and there a really good Bobby McFerrin one that is mainly a solo McFerrin gig, but Bona sits in for a 10 minute jam that is just amazing - mainly for their interplay and singing - but he does do a litttle solo thing.
I also recommend an album by Joe Zawinul Syndicate called 'Faces & Places' - the last tune has a particuarly wicked groove by him.
Cheers
Mike
PS Look here as well:
Richard Bona - Live Video