A new build of the Application Express Listener was just loaded.  This new version adds lots of new features. Check out the Configuration in the install guide.  Here's a screenshot of some of the new options available.

Another new thing is in the log file.  Every 1000th request I print some statistics to the log file.  The statistics include uptime, processing time , min/max/avg/median times for the requests.  Here's an example of those statistics where the listener has been up for 9 hours for a total of 16 minutes of processing time to deliver 79.1M of data.

Current Time:    Wed Dec 02 10:06:02 PST 2009
Server uptime:   0 Days 09:01:32.126
Total accesses:  1.95K
Total Traffic:   79.1M
Total Processing Time:    0 Days 00:16:52.965
Min/Average/Median/Max Processing Time:    6    506    308    12057ms
Min/Average/Median/Max DB Time:    0    288    205    9077ms
Active Requests:    0

1/3 active/available in cache apex