What do you use to monitor your web application?
dryicerx: If you're addicted to every statistic possible, check out collectd  http://collectd.org/ . It's a tiny daemon that polls every couple of seconds pretty much every server and services stat imaginable (cpu, mem, disk, snmp from routers, get vals over http from your app, apache, *sql, etc) without really any noticeable performance hit. You can output it all RRD files and view it in a variety of ways. You can also use use cacti, munin (by them selves to collect and graph, or use collectd to collect and use either of these to graph as well)