A pre-compiled version of Erlang for iOS are now available here: Erlang for iOS (1859)
Unzip the file and put the content in /usr/local/erlang on your iOS device.
I’ve now corrected the filenames in the /lib-directory.
An updated version of Erlang is available here now: Erlang iOS SSP255 Updated (2013) (The old version is available here: Erlang for iOS (1529)
The only change in this version is that the stack size pointer is set to 255 (Instead of 256) which seems to be working nice with iOS. If you have the old version of iOSErlang you have to give the argument +sss 255 to the ./erl command in order to run Erlang.