memory_limit

All the boxes (redhat or suse) I've worked on have had a default memory_limit of 20M or 10M. Does anyone else think that this seems low? I've gone through and raised them all to 100M. I know that my app is a lot heavier than most php webpages, but 10M seems very low to me. If you have an average database then you will go over 10M with a simple database query.