arrangement of crowded labels

Dear R users

I'm looking for algorithms that assist in spreading out crowded labels, e.g. 
labels of points in a scatter plot, in order to obtain a nicer visual 
appearance and better legibility. 

I'm probably just stuck because I didn't find the right key words for a 
successful search on the R websites or in the mailing list archives.

Any hints are appreciated.

Thomas Zumbrunn
University of Basel