Meow also has the ability to ignore any notifications that you wish to, well, ignore. This list of "to-be-ignored" information is persistent and remains across launches, which is helpful when you're doing development work.
Additionally, Meow can make use of the Growl notification framework. While it's fun to watch the Growl bubbles fade in and out as notifications bounce around the system, this may wear on you, but consider this: you can configure Growl to send all Meow notifications to the console or to a log file. "Ah-hah!", you say, "this'd be great for building up plists or simply logging what's going on!" Exactly my point.
Why would you want to use Meow? Well, perhaps just out of curiosity. More likely, however, you'd want to use it to track certain events during your own application development.
Meow is free for your use. Of course, any donations or nice comments are always welcome. If you wish to redistribute Meow you must first contact me.