I just discovered something pretty cool on my mac this morning and wanted to share. I use Symfony (http://www.symfony-project.org/) to develop web apps and it has a log file that you can use during development to help you debug certain aspects. I discovered that you can open the log file with the mac console.app:
and it will automatically refresh. I normally open up a second terminal and run tail on it:
tail -f log/backend_dev.log
but this is pretty neat as well. You can also use all of the console features such as clear display, insert marker, and filter. I imagine this works with any type of log file. I just happen to stumble upon it with the symfony log I was working on. At any rate, give it a try and see how you like it.