Looking for better solution(s)

It's been 5 years that I have been looking over Application Security issues. It makes me wonder when I find myself and many others still looking out for some unsolved or better security solutions. Certain issues where we have broken our heads to get a solution, but at the end it hasn't been "enough" secure.

I thought it might be interesting to post my list of such issues for others to see things and get opinions on the same.

Still Looking for better (Secure) solutions for following points:
1. Implementing a strong Key Management solution for PCI Compliance. Customers trust products which can help achieve this compliance, however do not trust the bespoke implementation. I strive to get this done !!

2. Develop a better CAPTCHA mechanism to defend robots. A believe a real world user hates the current image version displayed. It has to be simple and secure.

3. Get the NAT'ed IP address of the user using HTML or Javascript.

4. Strong solution to prevent users from getting on to fake sites (Phishing) without much of user education.

5. Developing an Effective and Manageable Web Application Firewall which can be at least a bronze bullet (if not a silver bullet) for Web Security. :)

6. Designing security for social networking sites where a feature could be exploited to be a flaw.