Went last year, and is truly an awesome place to visit. If you go, just be aware that it is a VERY popular place these days, and is always very,very crowded. I would recommend taking one of the photographer only tours - still crowded, but they do a great job of getting you in position to take a shot. Otherwise, all your pics will look like this ;-) It's like being a light-beam paparazzi !
I went there some years ago too. I have a lot of pictures of this wonderful place but no one is for sale because I've not requested (nor paid) the mandatory commercial permit ( http://www.navajonationparks.org/htm/antelopepermits.htm#photography )
These pictures are great!
I took some of secret canyon last summer. I've put in the request for the permit, called and tried again, in person when I was there but without any luck, so unfortunately I have no permit for the pictures I have. :-(