I don't know if previous releases have had this ability, but it's definitely in the 10.2 version of Stickies. If you double click on a Sticky, the note collapses into the title bar, much like window shade worked in OS 9 (and WindowShadeX does in X). It also puts the first line of the note into the title bar, giving a quick summary. This saves me so much space on my desktop!
Mac OS X Hints
http://hints.macworld.com/article.php?story=20020911063042505