I am no stranger to your predicament. I have to manage 12gb of log files per day. What I do is at the end of the day I have the logs ftp'd to a log box with around 100gb of storage. A perl script processes the files and pulls out information that I need to have on a day to day basis, not simply to look at them be able to recall specific information I only need. The files are the zipped up and moved to another partision which they sit in near line storage for 1 month. There after it's backed up into tape.
I hope this helps
CB