Many people may not know this, but ErlyWeb has an app.
It's called BeerRiot (http://beerriot.com), and its creator is Bryan Fink, whose been brewing it for a few months now (pun intended). He blogs about it at http://blog.beerriot.com/. (My favorite quote: "To those who are considering Erlang and ErlyWeb as a framework for their website: just go for it.")
BeerRiot is the quintessential web destination for beer aficionados. It has a beer database, user-comments, votes, and tags. It even comes in black and white background flavors. The only feature it lacks is letting you taste the beers somehow -- I guess I'll have to add this capability to the ErlyWeb todo list :)
According to my highly unscientific and subjective performance tests, BeerRiot feels very fast. I measured page load time with YSlow, which reported just 0.2 seconds for the homepage.
Kudos to Bryan for making such a nice app, and for being the first person to create a production ErlyWeb app.