As a 90 hour private pilot, I had rented a Cessna 172 for
a local solo night flight.  The moon was half shining and
the skies were clear as I called CTAF and entered a downwind 
for runway 31.  On final I was high and applied full flaps.
The landing was normal, so I put the flap lever up and
applied full power (and carb heat off) for the touch and
go.  The plane lifted off after a long ground run and 
was not climbing.  I pulled the nose up and saw the airspeed
drop dramatically, while applying a lot of right rudder.
I found that I could just maintain altitude if I used no
rudder and kept an uncontrolled left turn (at 100 feet AGL).
After 180 degrees of turn, I discovered my flaps were still
full down!  I retracted them to 20, and continued a normal
climb.  
  I was unfamiliar with the spring loaded flap lever, since
I used the settable flap handle on the 152 for training and
had only 1 hour in this 172.  Thankfully I had only half 
fuel and no passengers or the 172 wouldn't climb at all.
  I now do all night landings to a full stop and never use 
more than 20 degrees of flaps at night.