If you need to record and edit voice memos on your Mac, there's no easier tool for doing so than Mementum (US$4.99) from AllGoritm. It lets you record vocal memos, then sort your recordings by categories. You can also write accompanying text notes. With version 1.1 it adds new keyboard shortcuts and interface improvements.
The latest version also sports a global hotkey, double operating mode. Plus, it offers remind preset controls for "time snooze."
Voice reminders -- or any other sounds -- can be recorded via your Mac's mic as a new reminder (just make sure you have the correct Sound Input source selected in Mac OS X's Systems Preferences app). Click the Record button or use the global hotkey (Cmd+Shift+M) and Mementum will immediately start recording.
Click the Record button when you're done -- or press, again, Press Cmd+Shift+M -- and the app will save the recorded item. You can assign a name to the recording; if you don't it will be saved as a generic recording with a title akin to "Record 2013-04-24 15:46:05."
When you save the item, you can assign it to one of several categories: Overdue, Completed, Notes, Leisure, Finance, Meeting, Calls, Important, Other or Work. All your recordings can be sorted by category. Alas, there's no way to create a new category if you wish. Regardless, you can use Mementum as a storage for all your reminders until you decide to erase them or use them again.
After you've made a recording, the software will give you a reminder in 15 minutes by default. You can change the time to 30 minutes, 45 minutes or 60 minutes. If that's not enough, a customize button summons up a calendar and clock so you can set a voice reminder for a particular time on a particular day. That's a very useful feature.
Not everyone needs a voice recorder. However, if you do, Mementum is inexpensive and very easy to use.