Now that Mac OS X supports Emoji, they can be added to the title of a terminal window to help distinguish shell windows.
One application that has been updated in Mac OS X Lion is the venerable Terminal.app which finally supports 256 colors. While playing around with Emoji characters, I realised they were quite useful to mark different terminals. I typically have multiple windows open with local and remote shells, along with a python interpreter. Previously I used the background colour of the terminal to distinguish the various contexts, but now I also add an relevant Emoji in the title.
To add the character to a Terminal window's title, just go into Terminal » Preferences, select the Settings Icon and the Window tab. In the Title item, you can enter the emoticon in the title text by going to Edit » Special Characters and select the Emoji set. Double-click the character you want to insert.
I posted some examples and an image on my blog.
[crarko adds: I tested this, and it works as described. This did make me smile.]
Mac OS X Hints
http://hints.macworld.com/article.php?story=20110819143655157