Axis labels

Hello R-experts!

When I produce a plot R takes avoids overlapping axis labels in order to
maintain readabilty which is great. But now I have written a little
custom plot function in which I set my own labels and label
positions after generating the actual plot:

axis(..., lables=c('A', 'B', 'F', 'G', 'M'), at=mypositions)

As you may have guessed: This is categorial data. But the labels (and
categories) are unevenly spaced. I need to make sure, that all labels
are printed. Is there a way to tell R not to care about overlapping
labels or even better automatically reduce font size or scale the plot
to make everything fit? In my actual example letters would'n really
overlap - just get pretty close, so simply switching off this "distance
check" would solve my problem. 

I have read ?axis and ?par but couldn't find anything that seems to help.

Thanks for any hints.

	Philipp

Dr. Philipp Pagel                                Tel.  +49-89-3187-3675
Institute for Bioinformatics / MIPS              Fax.  +49-89-3187-3585
GSF - National Research Center for Environment and Health
Ingolstaedter Landstrasse 1
85764 Neuherberg
Germany