The developers behind ParanoidAndroid have been busy building incremental updates to the popular ROM. It's usually a few bug fixes and a couple new features, but the newest version of ParanoidAndroid contains something super-cool. Halo 2.0 has been demoed on video as part of PA 3.97.
Halo is ParanoidAndroid's custom multitasking system that works on the same premise as Facebook Chat Heads. A tiny floating icon can be used to retrieve notifications and background apps without leaving the current application.