I own these. They are awesome.
They especially especially amazing around water. I was in hawaii for 10 days and wore them 90% of the time. You can jump in the pool or ocean, then jump out and do whatever you want with out thinking about it. They dry extremely fast and don't slosh. I wear them all the time camping, swimming, kayaking etc.
If you plan on running in them I would recommend the pair they have specifically for running which have a little more padding in the sole. Bikkala I think is that style.
Takes a couple days to get used to them, and your calves will burn as you get used to using muscles you normally don't while walking in normal shoes.
The stock KSOs are good on most surfaces BUT slick things like relatively smooth granite and rocks with algae on them.
Great shoes that I would recommend to open minded people for specific activities.
EDIT:
fiz said:
*snip* Don't buy them to go trail running.
What kind did he have? the sprint or KSOs would only be appropriate on non rocky terrain, The KSO Treks would be much better for trail running as those actually have some sole protection that the others don't.
Most of the standard styles only have a 2mm mid sole so it would be easy to see why that would not be good for trail running. You can feel every little pebble under your feet. The ones for trail running have at least double the mid sole and more rubber on the sole.