Windows Server event log backups

[Mellman]

we currently limit our log files to be 4-8MB. We are logging nearly everything so they fill up pretty fast. What do you guys use to backup the logs? I'd like to be able to keep say...2-4 weeks worth of logs, but not keep all the events in the event viewer because it tends to slow down when the filesize is too big.

I can write a script if needbe, but figure we can't be the only ones who want to do this.

Thanks!
-Matt