Centralizing your logging to a hardened server might provide what you need. Better yet, if you can capture the logging into a database on a hardened server, you open up all kinds of possibilities.
I hate to bug you about this, but what kind of logging are you talking about? NT Event log? Unix(y) Syslog (and friends)? Logging from a minicomputer? A little more info might lead you to a known solution for what you're looking for...
2009-05-18 Re-Edit:
If you can get all of your data to show up as a syslog-style entry, then this will work for you.
For Unix(y)-style machines, use whatever syslog facility is in the box. You will want to ship off all data that is recorded to the central log server, but also, leave the stock settings for recording logs locally. (more on that in a bit)
For those Unix-style services that do not produce "true syslog" output, there are usually reparsers that can regenerate the data into something useful. Prime examples: apache and squid have log formats that, for most installations, are not formatted for syslog. Regenerate that data on a half-hour basis (or whatever works for you). The central log server then runs out and picks the data up for its digest.
For Windows-style machines, use NTSyslog, which is a free service that will shunt event log entries to a network syslog server. A quick how-to is available that covers setup.
Once all machines are "logging", you'll need to designate a central logging server. Go to the Splunk website and read up on it a bit; when you're ready, download it to your central logging server, and install it on this machine. The free version handles up to 500Mbyte per day, which, unless you have a bat-crazy amount of logging to contend with, should more than suffice. The splunk service will accept all of your syslog input, catagorize it, and store it in a local database. From a webpage, you can filter, select, see events by time, etc. Very handy for seeing a composite picture across systems. It can also hook up to a variety of different data "sources", including flat files, which means those apache and squid logs can be transformed into entries by splunk (provided you hook it up to each machine that requires it).
A helpful side-effect of this setup is that all of the local logging data is still there - nothing is lost, so even if your central log server goes down, the logs are valid elsewhere. And if the machine is lost (hdd blows up, security breach, whatever) you still have a history of the data on the central server.
Once all your machines are syslog'ing and your service is splunk'ing, point all of the syslog machines at the splunk server.