When i view my heroku logs on the server (with heroku logs --tail --app myapp) i see something like this:
heroku logs --tail --app myapp
2011-06-21T14:09:25+00:00 app[web.1]:
Rails doesn't generate those logs when in production mode. http://groups.google.com/group/heroku/browse_thread/thread/d778fafedc9a378a