Just found a great little article that introduces Ruby to PHP programmers.

While Ruby’s documentation is at a point now where beginners can start digging in and learning quite rapidly, there appears to be a learning curve with developers coming from other languages. Ruby is a language that took the best ideas from many languages such as Perl, Lisp, Smalltalk, and others, and while some syntax is immediately familiar to a PHP developer, the more you really unlock the power of the language, the less it looks like anything we’ve seen before.

It’s definately worth a read.