Mac: We've long been fans of Simplenote, the great syncing notetaker for iPhone, recently Android, and now OS X. It makes keeping track of little bits of text easy, providing a more minimalistic approach than the much-loved everything bucket Evernote. Now all the features you loved on your smartphone and tablet have come to the Mac.
For a long time, Simplenote functioned just fine on the Mac through an application called Notational Velocity. The downside with Notational Velocity, however, is that it can't sync every detail of a note (such as bold and italic styling) or take advantage of some of Simplenote's nicer services like automatic versioning. If you've used Simplenote before, downloading the free app is a no-brainer. Otherwise, you should check it out if you're looking for something minimal yet highly functional for minimal note capture.