If you have developed methodology for summarizing affymetrix probe level data to expression measures we would welcome a submission to the "friendly competition" described here: http://affycomp.biostat.jhsph.edu/ you can also use the described tools to compare methods without entering the competition. the results of the competition will be announced here: http://eci-events.com/AffyGeneChip/ rafael ps - the results page is constantly being improved... but its functional.