I am a big fan of commentable document software, from digress.it to co-ment.com. We also built our own “MakingSpeechesTalk” software for Commentneelie.eu. Yet this kind of software is not yet widely accepted.

If I want to engage the widest number of people, which software should I use? Is GoogleDoc the most accepted way to comment on a document? Or maybe this is still so niche that I just need to pick the most usable one?