Ulf Wiger has been experimenting with making Erlang indentation-senstive. He followed up with a Part 2 after comments.
For most people who start working in the Erlang language, the most annoying new concept is all the various line-terminators you have to know. Damien Katz sums this up nicely. All these explicit terminators might make other people's code easier to read but writing code should be easy too (they are equally important). Mue says just get over it but as a Python user I agree that Erlang would be way better off if it was indentation-based so this was an interesting experiment.
As for Python, I'm still shocked to hear people say "Python would be nice ... if it wasn't for that whitespace thing." Who is perpetuating this? I have no idea. The next time you hear someone say this, pass along Python: Myths about Indentation!