Yes, check out Banjo in the Hollow. My husband plays Banjo too, but not clawhammer. There lots of informal jam sessions all over the triangle and he hasn't had any trouble finding jam sessions to go to. Finding the time is another matter. :-)
Also, you and your husband have probably heard of this already, but MerleFest is a huge bluegrass festival that is held each year in North Wilkesboro on the last weekend of April.
MerleFest 2008 There are tons of musicians there and you can find all styles represented.