Mobile Apps

I've become really interested in how architects communicate about standards with colleagues in an organization.

Questions arise on teams such as "why didn't you use X?", "how was I supposed to know we use X?", "we want to try Y on this one", "what was good or bad about Y for us", where X and Y are tool-kits, vendors, or procedures.

I had imagined that in the age of wikis and +1s there would be some way to post best practices for various domains (databases, languages, modules, web services etc), get feedback, identify alternatives being pursued, and share results so individuals are aware of and contribute to evolving shared standards.

I'm not convinced the answer is "just a wiki", or at least, I can imagine some additional templates or structure being useful here.

What formats or platforms do you use to express best practices? What ensures popular critique and proposals for change? How do you achieve transparency into alternatives being pursued?