Winfield Kansas (3rd weekend in Sept)
Merlefest (3rd or 4th weekend in april)
Rockygrass(4th weekend in july)
Renofest (March sometime)
Wayne hendersons (second weekend in June)
And some others
Utah state championships (july or August)
Fire on the strings (3rd weekend in may)
Ossippee valley (same weekend as rockygrass)
When I get a chance later today I'll be more specific on times.
The Ossipee Valley contest is the New England Flatpicking Championship. It is always on the Saturday of the festival. I've seen some pretty great players there. Lately the prizes have been 4 guitars with winner taking first choice. Last year guitars were a Conley, Bourgeois, Taylor and a Collings. http://ossipeevalley.com/index.php?page=ne-flatpicking
2008 will be the six year of the Minnesota Flatpicking Guitar & Duet Championships to be held at the Minnesota State Fair Heritage Stage over Labor Day weekend. Besides cash awards and trophies for the winners, all entrants and accompanists get contest T-shirts and free State Fair gate passes. For info, www.minnesotabluegrass.org/calendar/contest/index.html.
Here's one that will sure be worth the trip if you win!
May 30 & 31st, Wartrace, Tennessee is having a music festival with a guitar contest & is giving away one of Stephen Gallagher's newly designed red spruce topped G-55's! Stephen had one of these light, responsive & powerful new models with him during his last visit to my shop & I'll have to say that the G-55 was one of the most impressive guitars I've played. Great job, Stephen!
A couple more for you:
Oyster Grass is in Kemmerer, Wyoming and is the Wyoming State Championship. It was last weekend http://www.oysterridgemusicfestival.com/ The dates for 2010 haven't been announced, we will
have to let the organizers catch their breath.