Ever since Sam Bush and Company formed New Grass Revival in the 1970s the term "newgrass" has been somewhat problematic. When Bill Monroe pioneered the genre of "bluegrass" out of traditional "old-time" music, he (IMHO) never meant to pigeon hole his particular style of music. So, I don't like the term "newgrass" but hot-damn, I sure do love the stuff that gets filed under the label...
Trampled By Turtles:
Link to a TBT SBD recording from 07-20-2007
Here's some Cornmeal from Jam Crusie 9 (2011-01-05)
Well, all things considered, it'd be wrong to not include a little New Grass Revival in this post!