Ever hear of Parsix? I hadn't until I was looking for something to replace Xubuntu on this laptop for fun. It's, I guess, a combination of Parsi (romanized phonetic of the Persian language name) and Linux. Parsi+x. Makes sense to me, at least. The lowdown on Parsix is that they just released the 1.0r0 version of their flavor on 25-01-08. It features a slick, black and blue GNOME 2.20.3 theme, 220.127.116.11 kernel with CFS v24.1, and a nice little set of starter software for the liveCD.
The coolest thing about this wave is that you can see region and language specific distros popping up all around the world. For example, the Fedora-based Linpus distribution which is the first Chinese distribution to support UNICODE. It's now up to version 9.3, and is the first distro to pass LSB 2.0 Certification. There's a report of high hardware compatibility too, so you don't have to do a lot of driver-shopping.
Aside from just the OS, there's plenty of open source software which is being converted into all sorts of languages from Afrikaans to Zapotec. The only problem is having to do complex keyboard mapping or work-around solutions for when you need to do something in another character set. One of the ways Parsix makes it easier for its users to exist both in the ASCII world as well as their own is a simple Alt+Shift shortcut which switching from the ASCII characterization to Parsi.
For the Greek contingent, there's an option of Knoppel, a localized version of Knoppix, and Zeus-Linux. ZL is a Slackware clone, but they updated it and did some bug-fixes to make it worth your while. Currently, they report not having a Greek-language installer, but they're planning on releasing one as of v2.
But open source stretches beyond just language, price, and culture barriers. It can now be on your cellphone via Google's Android OS. Android uses a Linux kernel! Hopefully, this will be the big break all open source developers and users are looking for.
So, if you want to play around with some localized versions of Linux, just Google up some of these or many others and give them a try!