MacDroidNotifier is a very handy application that lets you receive notifications when certain events take place on your Android phone. The utility works in conjunction with an Android app to display notifications. You need to have Growl installed, or you won't get any notifications. Growl still can be found for free, you just need to download an older version because the new ones are $3.99.
Once you have installed and set up the Android and Mac applications, you can click on the menubar and access the settings. From here, you can choose the notifications that you want to receive. By default, you will get notifications when you receive a call, SMS message, MMS message, and notifications about your third-party apps and battery status, such as low battery, plug in charger, etc. Besides showing notifications, the app can assign actions to any of the available events. For example, the app automatically mutes your Mac when you receive a call. You can also copy the text of the notification to the clipboard, or execute a file or script. Unfortunately, you can only add one script for all the events.
Security is always important, and this app lets you add a passphrase that you can use to prevent unwanted access to this notification solution. The password will need to be entered for both devices to be able to communicate with each other.