Do you have photo proof? Just kidding. 
There
is a Singles Meet & Greet on the first night onboard at 11:30pm at
the 21 Century bar near the casino for those over 35. Another
place would be the piano bar. Depending on the piano player,
sometimes it is hopping.
Another place to check out before you go
is Cruisecritic.com Look for Rollcall, then the name of the ship,
and then the date of the sailing. Usually there are plenty of
people posting there.
Dave
Upcoming
CCL Fantasy 11/10/09 6-nights from Mobile

NCL Spirit 11/22/09 from New Orleans

CCL Triumph 02/13/2010 (out of New Orleans)

Sailed
CCL Conquest 09/02/07
CCL Fantasy 02/07/09; 11/01/08; 04/10/08; 10/11/07; 09/17/07; 01/18/07; 11/27/06; 10/30/06
CCL Holiday 09/02/09; 09/22/08; 08/30/08; 01/29/07; 12/04/06; 10/23/06; 09/30/06; 09/11/06; 09/03/05
CCL Elation 01/23/06
NCL Spirit 11/03/07
NCL Sun 02/09/08; 01/23/07; 10/23/05
NCL Dream 10/31/04
USS Frederick LST-1184 12/14/81 (USMC)