You could also look into Failtale, it’s really neat (and open source). Saw the presentation of these guys on the last Arrrrcamp and was quite impressed. They probably could use some contributions too from the community.
I’m seriously considering throwing out EN soon and replacing it. EN was nice when there were no alternatives, but being spammed when customers click 20 times or having the app hang if the SMTP server goes offline or goes wonky… time to look into something better imo.
For Rails/Ruby apps you can use the failtale-reporter gem to send errors over automatically.
Peter De Berdt