Monitoring memory use

[Kent Johnson]

How can I find out how much memory is used by a cron job?

Background:
I manage an account at WebFaction. It has a memory limit. I have a cron 
job that runs every night, it generally is not a problem, but last night 
it chewed up a ton of memory and triggered a limit alarm at WF.

I don't know how their alarms work so I don't know if this was an 
isolated event or if it is using a lot of memory every night and I just 
got caught last night. I would like to find out. Is there some way I can 
wrap the cron job to log the memory used by the process?

I think the server is running RHEL, don't know which version.

Thanks,
Kent