Disk Alarm is a very useful system maintenance tool. Its main function is to warn you when your disk space is low. You may be thinking the same thing I was thinking when I found that out: Mac OS X already warns you when your hard drive space is getting low. And that is true. But Disk Alarm lets you customize the way you are alerted and when.
From the application's main window, you will be able to set the volumes that you want to be alerted of when their space is going low. You can also use a sliding bar to specify exactly when you want to be warned. This bar can go from 1 megabyte to almost the full capacity of the hard drive in question. When the space is getting low on your hard drives, you can have the application do a couple of different things. The default action is to show you a warning, to which you can also add sounds. But you can also have Disk Alarm send you an e-mail using Mail.app when the space is low.
Disk Alarm checks your hard drive space every 1 minute by default, but you can change this to any value between 1 and 120 minutes.
In short, Disk Alarm is a nice tool to have installed if you are always running out of space on your Mac. A nice advanced warning system can help you avoid problems.