I just saw this duo (Rodrigo y Gabriela) at the Boulder Theater last night and they kick ass. It's lively dualing acoustic guitars with Mexican roots, but includes techniques from heavy metal (both were metal heads) and other influences. It's fast moving hands and use of the guitar as a percussion instrument.

Their own music is fantastic and they also do cool covers of rock songs (Metallica, Pink Flyod, Zepplin, White Stripes, etc). Check out their website at http://www.rodgab.com/ and if you like the demo song that plays, I highly recommend picking up their album (they sell it on their site, but it's cheaper via Amazon since they are selling from Europe). At the concert they were selling the version that also comes with a DVD, but it doesn't look like they sell it online.

Unfortunately, last night was the last stop on their US tour, so you'll have to wait to catch a show, but if you get the chance, I highly recommend it.