Not the best tutorial ever, but I found it helpful.. It describes a fairly simple, but non-trivial task (creating an RSS feed from your email inbox, generating the RSS feed, and directly interacting with the POP3 protocol over SSL)

Also, most of the code will require slight modification to work with the most recent version of Erlang. This seems like a bad thing, but it forces you to actually understand the code and determine what broke, rather than just copy-and-pasting everything.. For example, the regexp module had changed name, so I prodded around the erlang library code to see where it went, and if the arguments had changed - in doing so I realised how simple (most of) the code was, something I wouldn't have done if the tutorial was "better"..