I have been looking through scubaboard.com's Accidents and Incidents forum. They have a place where other divers can share their "Near Misses and Lessons Learned". In this forum, divers can share what went wrong, what they did and what they learned from it. The rules of the forum are that it is a flame-free zone. You can see for yourself what responses there are like: http://www.scubaboard.com/forums/accidents-incidents/ (click on "Near Misses and Lessons Learned").
The main ideas supporting this forum are that each diver is responsible for his or her own safety, and that by sharing openly without fear we can learn from each other's mistakes.
Indeed, I agree with npallasi on this. Having an area where divers are able to share their experiences and allow others to have case studies to learn from will be good.
I feel that most dive agencies in general are not putting enough stress on the risks involved with diving. And even if they do, they only touch the surface without the clear cut seriousness about the issue. It's probably too much to go Army style, with pictures of accidents and such, but it would be great to incorporate real life stories and case studies into theory lessons, even for Open Water Diver courses. It allows the (potential) divers to think through if they have the sufficient skills and confidence to take on the course, or if they require more practice.
Dive centers themselves should allow divers who are not confident of their current skills to change their course/trip package if necessary. For example, a diver with 5 logged dives signed up for an Advanced Open Water course, but upon attending the theory lesson, feels that he/she is not confident for a night and deep dive. The dive center by allowing him/her to switch to a leisure trip - and refund a portion or offer a discount on the next course - will definitely promote a safer thinking attitude with their divers.
On the diver's part, the buddy and divemasters/instructors should be informed if they are using any new equipment. I've seen a few divers purchase new gear from shops, and take the new equipment on dives immediately, and they really mess things up for themselves when they aren't familiar with their configuration. I've seen a scenario, where the diver got so stressed up with not losing his pointer, and clutching to it all through the dive, he didn't even clear his mask and was struggling to see. His buddy was away snapping pictures and the dive guide was at the front of the group.
As much as scuba diving is proclaimed as a buddy sport, being self-sufficient is the way to go. No buddy is able to stick by one's side all the way through and be their "backup". It's always the diver's onus to be responsible for their own safety by having their own backup equipment for redundancy and learning how to use them. It's pretty much like driving - if you have a flat tire, you may have a spare but not know how to change it, you'd still need someone to stop by to help. Maybe you'd figure it out eventually, but the difference is that in diving, every second matters.