Meant to include this with my challenge - as you don't seem to have done one before... http://365project.org/discuss/tips-n-tricks/7780/water-crowns-tips-and-tricks it's a great tutorial - hours of fun and maybe frustration guaranteed. For refraction (I had this challenge the first week) google refraction and check images - stacks of ideas on there either to emulate or springboard off!
You may have something already but we had a camera challenge for the light art a while back. There is some links on here too. http://365project.org/discuss/themes-competitions/13296/camera-settings-challenge-8
http://www.youtube.com/watch?v=jvQejjxg960