Here's the James Hill mixed with Jake Shimabukuro, Aleksei Arkhipovsky, of the Balalaika. This man has lightning quick fingers. Faster, faster, faster.... WOW!
And Roy Smeck showmanship...
THIS VIDEO IS 10mins LONG -- DO NOT MISS IT!
HERE's some detailed information about Balalaika tuning and several songs. The thumb is used quite frequently in the chord shapes http://www.kaikracht.de/balalaika/english/school/school.htm