Warn users when websites are known to have issues with Tor
Just like Firefox for (or is it Chrome?) display a warning bar on top of the browsing window to advertise that a website might be malicious, we could provide a similar feature for websites that are known to have issues with Tor.
This opens a whole can of worm about how the list of site is curated, but we could start with just an hard coded list of the Alexa top 1000.
That would definitely help people understand what's going on with Google (captcha) or Craigslist (blocked).
One thing to keep in mind is translation, and so we might want to define a set of common issues ("blocked", "captchas", etc.) to choose from.
Feedback from the sprint by localisationlab.org at CTF Valencia 2015.