If you’ve been looking for a Stickies-like application with just a tiny bit more oomph, you might like to try SpiralBound.
It looks quite a lot like Stickies, but there the similarity ends. SpiralBound emulates a notebook, rather than a pad of sticky sheets, so in use it feels quite different.
Your sheets stay in the pad, for one thing. Unless you tear them off, of course. All notes are searchable (including the torn-off ones), and lockable with a password if you have notes you want to keep private. At the bottom of the pad there’s a drop-down list of all your notes, which makes it easy to jump around between them.
The basic version costs five bucks, or you can spend $10 on the Pro version, which adds multiple notepads and a notepad sorter window for better organization of entries. If you switch to it from Stickies, it can automatically import all your existing Stickies notes.