The yardstick we are using to know what the bugs are is the Bugzilla system 
that is installed on the Jakarta web site <http://jakarta.apache.org/bugs>.  
You can help us out by keeping the following principles in mind:

* If you think you've discovered a bug, please review the current list
  of bugs to see if yours has already been found by someone else.

* If this is a new bug, please record it in Bugzilla.  Bugs that are
  described only in mailing list messages will likely get missed in
  the heat of the bug-swatting battle.

* Proposed patches (included in the bug report or as a separate
  attachment) are deeply appreciated, because they speed up the
  fixing process.  (Besides, you get your name recorded for posterity
  as a contributor! :-).

* Many bugs have been fixed in CVS. If you want to help find the remaining 
  ones, you can grab the most recent nightly code drop and/or check out the 
  code from anonymous CVS and build Tomcat yourself.

Thanks for all the sharp eyes looking for problems (and contributing
fixes)!