Great advice, ricree and m_fish. I think this is right on. That's why I don't want to learn Python - it looks like a great language, but I already have Ruby. I've been trying C and Scheme on the side, but through reading (SICP and K&R), and I've kind of hit a wall. I really want to put something into production that isn't written in Ruby, and an iPhone app would do the trick.

If reading SICP or K&R doesn't fire you up to write code, reading, say the Armstrong erlang book or the haskell books (intros by Hutton, Hudak,) won't do it. I think most of these languages, you can look in delicious and see everything that's been tagged on erlang, haskell, scala, factor, whatever, in the last week, what they're being used for, gauge quality/depth of toolset (emacs/textmate support, debuggers, unit test/BDD, profilers, etc), get ideas there.

great thread BTW , mazeltov

Well, learning C will help with the Obj-C side. If you want to learn iPhone programming (I'm picking it up myself, but I have a C background), there are several meetups in Silicon Valley.

What wall, out of curiosity, are you hitting with C?

Understanding the development cycle of an application. I can fire up vi and complete exercises, or build an artificial tool, but that only takes one so far.