To add Emoji to your folder titles, first open a text box in any normal application and go to the Edit menu and select 'Special Characters.'
In the window that pops up, go to Emoji and pick out the characters you want. Double click to add them to the text box you're in, then copy them to the pasteboard by selecting them and pressing Command+C. Finally, open Launchpad, open the folder you're interested in, click on the title text, and press Command+V to paste it in. Et voilà, you've got a spiffy looking Launchpad!
This tip can also be used for iOS once you've turn on Emoji support there.
[crarko adds: This is more of an Easter egg than a hint. Still, it's good to note the existence of the new character symbols. It's too bad there's not a Dogcow in there.]

