Using an RaspberryPi for watching greek TV channel for free

Hello all. I own a RaspberryPi and I would like to use it for watching greek TV channels. I have heard that it is possible through XMBC player by receiving a stream of Internet. Is it possible to watch channels like ANT-1, ALPHA, MEGA, STAR, SKAI, ****cinema, Supersport, etc... but also the german encrypted *** channels? Is there any tutorial on how to set up a Raspberry Pi for using it like a streaming client?

Any help appreciated. Thanks

I have installed OpenElec and did add Fusion and Lambda's Hellenic TV repository. But when I try to open Video-->Addons-->HellenicTV nothing happens. Am I missing anything?

I think I have forgotten to add Lambda's repository. Now it works... but I'm kinda unsatisfied with OpenElec although it's stated to be the most light-weight XBMC distro out there. It is hanging, has lots of delays when entering/switching/leaving menus, etc... I think I have to try Xbian and Raspbmc, too ? is there any other channel available which streams greek TV channels than Lambda ?