Meaty examples using Erlang. I’ve found that reading lots and lots of code in whatever language I’m trying to learn helps me pick up the language faster:

http://www.erlang.org/examples/examples-2.0.html

Written in mostly the same style as Eckel’s “Thinking in X” series:

http://chuffyrodents.org/erlang.pdf

Pointers to several articles about macro programming in Erlang:
http://jroller.com/page/murphee?entry=metaprogramming_erlang_macros_from_ground

A treasure trove of docs related to Plan 9 - the distributed OS from the people who created Linux:

http://plan9.bell-labs.com/sys/doc/

For programmers interested in esoteric languages like Scheme and Erlang, here’s a couple of pretty useful cookbook-style resources:

Erlang Cookbook: http://schemecookbook.org/view/Erlang/WebHome

Scheme Cookbook: http://schemecookbook.org/

http://www.acm.org/acmqueue/digital/Queuevol5no4_May2007.pdf — starts on page 50

Writing a feed aggregator in Erlang

http://www.erlang-consulting.com/aboutus/erlangarticles.html

http://www.youtube.com/watch?v=dGNs7QMeV7E