Beyond tab management (which was exceptional), the side panel was and is my favorite UI widget hands-down. In the same vein as hot-corners, being able to 'toss'

Beyond tab management (which was exceptional), the side panel was and is my favorite UI widget hands-down. In the same vein as hot-corners, being able to 'toss' the pointer into the edge of the screen to open mail, notes, etc. felt just plain better than other methods.