Here be various efforts to explore aspects of Erlang.
wxErlang (A popular tutorial on learning to create a gui using the wxerlang module)
gsErlang (The objects in the DEPRECATED gs module expanded and linked)
Some Erlang code examples (mostly about PIDs and message passing)
ErlBol (communicate via TCP/IP with Erlang as backend - using the obscure Rebol language as GUI, using Erlang's data types)