These are mostly from http://www.wackywet.com (mostly all clean), http://www.swimmingfullyclothed.com (beware some porn / gay porn galleries here; newer ones are well marked though), and http://www.getwetboys.com (wet life of kiev, all clean, 'walks' are self-model sequences though). All three sites are free.
Design science license. CC By-SA or GNU GFDL OK too. Copyleft is the goal.