What are some resources for learning Lambda Calculus?

Well, there's always An Introduction to Lambda Calculus. I've tried reading it a few times, but always got stuck. I have a nagging feeling that I already know most of this stuff and would probably have an easier time understanding it if it was presented in terms of Lisp/Scheme rather than math. You might have better luck, though :)

I found "An introduction to Lambda Calculi for Computer Scientists" by Chris Hankin to be pretty good, but I only really used it for one class - not used it in the real world :)

If you are done with the Wikipedia entry, follow its link to the online Structure and Interpretation of Computer Programs, do the assignments, or read the book.