Using non-latin characters as axis labels

[ptaeck]

Hello,
does anybody know how to correctly input greek letters into the graph
labels? I suppose I will have to use some additional library?

Secondly I would like to edit the tilt of x axis labels, as it seems
to be a bit funny with one whole numbers lying under the line (see
default example http://i40.tinypic.com/9a8mm1.png).

Thanks for any help!