LaunchBar enthusiasts may already be aware of this, but I stumbled upon the ability to add reminders to … Reminders (I now have visions of Austin Powers running through my head). It's quite slick.
The key to remember is that the Reminders application from Apple uses lists. If you've never modified from the default, then your list is called Reminders, as shown in the image here. Simply type the name of your list into LaunchBar, then press enter to open the dialogue you see here. Add the description for your reminder, then a due date if desired. The due date comes after the right angle bracket (>), which can be created by pressing tab if you're a lazy typist like me.
Little things like this were what drew me to using a Mac years ago, and they continue to delight me today.