Mac: Notification Center on Mountain Lion is great for keeping track of all your notifications, but we're still waiting for our favourite Mac notification app Growl to update with support for Mountain Lion. While we're waiting, Mountain Growl is a free app that pushes Growl data to Notification Center.
We've previously mentioned Hiss, which also tries to solve this problem, but Mountain Growl approaches things a little differently. Both apps push Growl data to Notification Center, but Mountain Growl also keeps full Growl support. This means if you use remote notifications or Prowl, you can still continue to use them in Mountain Lion. You also get a lot more control over which notifications you see.
If you've been dissatisfied with Hiss, or you just want to check out another option while you're waiting for an official Growl update, Mountain Growl is worth a look.
Mountain Growl [GitHub]