Apparently it happens often enough for there to be an individual keyboard shortcut to instantly swap the last two typed characters, and that keyboard shortcut is Control+T.
Open System Preferences and click on the Dictation & Speech pane. There, you'll find a checkbox for Use Enhanced Dictation. The first time you check it, you'll need to wait out a hefty (about 750 MB) download, but once you're done, you can dictate a lot more freely.
Now, transcription happens on your Mac (not Apple's servers), and you can see the transcription appear as you speak, in real-time. In fact, the cursor remains active too; if you see a mistake, you can click around (without speaking) to make your edits, put the cursor back where it needs to be, and start talking again.
OS X Mavericks also offer many speech-based editing tricks. While you cannot delete - if you say "delete that" OS X Mavericks types "delete that" - you can do quite a bit of other editing such as new line, new paragraph, plus tons of other symbols, spaces, capitalization and more. Here is Apple's KB article with a detailed list of dictation commands.
To activate it, hit Control+Command+Space and the popover will appear under your cursor. You can view recently used emoji and swipe down in the popover to show a search field that lets you find a specific emoji by name. You can also access the old-style Special Characters window by clicking the icon next to the search field.
While it may seem like a minor thing it can actually have a big impact on how fast and responsive applications are. For example, every time Adobe Photoshop, Microsoft Word or QuarkXPress starts, the application scans your fonts and builds a preview for you. After this, every time you want to change the font the application has to load these previews and display them to you, which in Microsoft Word can takes up to five seconds from the clicking the font menu until it actually displays the font list.
By disabling unnecessary fonts you can speed up applications quite significantly. As an example a quick scan of this computer shows that there are over 450 fonts installed, but typically only 20-30 are ever used. By disabling some of the extra fonts we can reduce the time applications have to spend on managing fonts.
So how do you disable fonts? You can use the application Font Book that comes with your Mac (you find it in Applications). Give it a few seconds to load your fonts then go through the list and disable the ones you don’t use by selecting Disable from the Edit menu. Damaged or duplicate fonts can also slow down your computer so while you are in Font Book select Validate Fonts from the File menu and verify that the fonts you have installed are okay. You can automatically disable duplicates by using the Look for Enabled Duplicates (or Select duplicate fonts on Snow Leopard), followed by Resolve Automatically option (or Resolve Duplicates option in the Edit menu on Snow Leopard). It is also a good idea to enable Automatic font activation in Font Book’s Preferences as it lets OS X re-enable fonts when an application needs it.
It is worth noting that the font caches themselves can become corrupted and cause slowdowns or crashes on your Mac so if you experience problems because of this it is a good idea to force OS X to rebuild the font cache. Cocktail makes this easy: open Cocktail and go to Preferences > Caches > User and select Font Caches. Next time you clear the caches Cocktail will make clear out the font caches too and force OS X to rebuild them.
Here's all you need to do to stick a Note on the Mac desktop:
• Launch Notes app in OS X and double-click the Note you want to tear off
• Position the floating note on the desktop and then close the primary Notes app window
Super simple to get the Note onto the desktop, but now for best part:
• Grab an iPad, iPod touch or iPhone and launch Notes app
• Locate and edit the same note, it will automatically sync and update on the OS X desktop