Martha wrote about calling parties.
Partly inspired by the Webster Grove calling parties, by the "house 
dances" and "Potter's Porch" tradition, and partly by the availability
of a dance space for $25/night, I've been organizing "Woodshed dances" 
for the last year and a half.  Callers split the rent, everybody else 
gets in free, and we get to sort out new choreography, puzzle out other 
people's dances, etc.  BACDS adopted the series (which means extending 
insurance cover and putting the info on the website) this year.
http://www.bacds.org/series/woodshed/atherton/
It's very helpful, and trying stuff out there definitely reduces the 
instance of crashing and burning in front of paying customers.  
(Challenges sometimes include trying to make a worthwhile evening for 
the three dancers who happened to show up.)
-- Alan