This should probably be in the DIY forum, but there is always a lot of threads on humidity here.

I set this up today and thought I would share it.
I haven't actually run it other than a couple of tests so far.

My tank holds humidity at around 45% if I do nothing, but when my snake goes into shed, like he is now, I spray with a water bottle to bump it up.

I thought I would try something to make it a little easier.

I bought a small submersible pump at a blow out sale from Grainger's for about $18 (reg. $50).
I then bought a little misting kit at Wal-Mart for $5. It had two nozzles a some tubing in the kit.
I bought a little more tubing and a "Y" connector, put a pail under the tank and voila...It sprays a fine mist.

Total cost about $25

I'm going to set it up to a timer to come on for a minute or two a couple times a day (I'll have to really dial it in so it's not too humid), but I think this might work.

I'll let you all know after a few days.