No it does not make my room noticably more humid, it only burns through 2/3 - 3/4 gallons of water every 24 hours of continous running.
Im actually still tweaking it out to get the best cooling possible, running my CPU and NB blocks in parallel helped.
I'm also building a external radiator for it for travel purposes. I am considering hooking this up to my bong right before the line to the shower. I figured I'd see how water cooled to room temp before applying evaporative cooling effects the system.
In addition I plan on insulating the feed line to the computer to reduce any temp change in the line due to running through 6' feet of exposed tubing. Although the rubber hosing is a pretty good insulator.
As far as the tubing, I found 2 sites, one sold in 5' the other in 10' but you had to cut it down to 8' or less to ship UPS.
www.usplastics.com is the link that I used.