Bryan Boyce February 16, 2012 01:12 AM I bought one of these for my wife, as a replacement for a larger, older humidifier. She loves its small size and silent operation. As for the length of running time, there is a switch on the back that changes the amount of humidity produced. Running at max, we get between 3and 4 hours of running time from a 16 oz bottle. It does turn off automatically when the water gets low. Though we rarely use it, I like it because of its size. Max Mad February 16, 2012 02:02 PM \"Air-O-Swiss\"??? That\'s funny, because I have that EXACT humidifier on my desk, named \"Worltec Humidifier\" by (I believe) a Korean company Ohsung (Happy Technology). (See link) http://www.homeandhome365.com/index.php?dispatch=products.view&product_id=31236(I\'m guessing Air-O-Swiss bought the rights from Ohsung???) Comments.... February 16, 2012 02:02 PM I bought one and it performs as advertised.....no leaks, quiet, very clever and compact design. How well it can keep your room comfortably humid throughout the night depends on a couple factors, primarily the size of the room and how well it is sealed from the outside environment. In my application, this unit made little difference to the room humidity level as measured on a hygrometer. I ended up purchasing an evaporative recirculating humidifier that does the job, but this larger unit is definitely not portable. coryatjohn February 16, 2012 03:12 PM I love the little travel bag... the exact size for the device.Now what do you do with that huge power block? I guess that just gets thrown in the suit case. Wombat56 February 16, 2012 07:41 PM Apart from the need to have a plastic bottle, In western countries ordinary tap water should be plenty good enough. The water should be low in bacteria to start with, and the ultrasonics provides an extra sterilisation affect. yrag February 17, 2012 02:06 AM Hmm . . . I hate humidity.I want just the opposite - something one could wear to REMOVE humidity from the body - I know it's a leap right now for the Northern Hemisphere, but I'm thinking of hot steamy summers already. Terry Penrose February 17, 2012 06:03 AM Wonder how this would work as a colloidal silver humidifier? Denis Klanac February 20, 2012 01:52 AM This tech has been around for a long time and is nothing new, try a search on eBay and you will find a huge variety of similar devices. I use one to grow my mushrooms, it works very well Thomas Roberts February 22, 2012 11:10 AM I can\'t tell you how many times I put wet towels over the heaters in hotel rooms to try and raise the humidity. These are an easy sell to any cold weather climate business traveler. RonC February 23, 2012 09:55 PM I\'ve had this model for over a year. I only need moist air while I sleep in the winter when the heater runs, and I don\'t need a big model to change the humidity in the entire room, so I put this on the night stand and it works perfect. The only complaint in reviews is that the LED light inside is too bright and disturbs sleep. I painted over the bulb with black acrylic paint.