Fast Confirm was born when I felt the need to ask confirmation to users on some actions performed on widgets. The small-sized nature of these widgets, and their ease of use pushed me to design a clean, non intrusive way of asking confirmations. A traditional dialog box, with jQueryUI for example would have disturbed the workflow a bit too much. I also needed something that clearly indicated from where the message came from.
So I decided to do my own plugin for this. It had to be lightweight, easy, clean looking, flexible but not with tons of options. So there is no auto-positioning stuff: if you decide to position it on top of your trigger element, it will be on top, even if it is off-page. It's your business to decide which side of your trigger element is suitable to receive the confirm box.
Since version 2.0, you can let Fast Confirm take care of the events management, which permits to use it really simply with form submissions for instance.
No more talking, go look at the demo and documentation pages. That plugin is pretty straightforward.