YUM: how to find out groups?

[Roger Grosswiler]

Hey,

I installed ruby, saw it was a metapkg in 'Development Tools'. So, i 
could install it via yum groupinstall ruby (which did not install eruby).

So i would like to find out, what further groups are available (are 
there lots more than mentionned in yum grouplist, it seems?)

And, if i know eg. i need to install package ruby, how can i find out, 
in what group this is?

Roger