hlStickyStack
Ahh, the sticky stack (isn't that catchy?). Using the sticky stack will give you super powers. Well, not literally of course, but it could be a handy functionality indeed. Stacks are a way to have multiple independent sticky elements working together. See for yourself and scroll this page. As soon as multiple sticky elements become sticky the others neatly adjust their offset automatically.
It could be useful if you have multiple ui element on your page that are on different places but still need to be always shown. And thanks to the service you can also get the current stack height or the height of the stack at a certain scroll position. This can be useful if you want to scroll to a certain position on the page but you're not sure how high your sticky element stack will be.