As a slight variation on the Apache rotatelogs program, DJB's multilog might be worth a look. It works in a similar fashion, except that it rotates based on the size of the file and only keeps a set number of logfiles. This way you can guarantee that your log partition will not fill up.

If you don't like the fact that it drops log files, you can set it up to mail them to you (not a good idea if you are talking gigs of data :) or do something else with the file that is about to be rotated out...

It also allows you to filter out log entries based on patterns, and lets you send the output to several different log files based on the patterns.