On the Make Me Pulse blog, there's a look at PHP6's support of Unicode in the SPL (Standard PHP Library) TextIterator handler.
I've just install the last version of PHP6 dev and I've decided to test the famous new feature, the PHP Unicode Support. I will not explain new things about PHP6 or Unicode or TextIterator, it's just my discoveries test on this features.
He steps through the process he followed - enabling Unicode support, testing various output methods (including just an echo and using the TextIterator) as well as some of the manipulation methods (next/first/current) that can be used to get certain characters out of a string.