It seems like Windows and OS X should focus on tiling if their true goal is productivity, but they have actually gone in the opposite direction in recent releases by focusing on full-screening apps.

I use sizeup (http://www.irradiatedsoftware.com/sizeup/) and multiple desktops on my mac so that I rarely have to touch my mouse to resize and organize windows.

I've also considered a tagging system for links - bookmarks are honestly far too much manual management - I'd like a quick hotkey and a tagging interface possibly hooked up with a calendar. I'd be even better to group context from multiple sources such as emails, calendar events, web links and chat protocols so that for my 3PM meeting it could load a screen with all the context I need, allowing me to set up tasks beforehand.

Wouldn't mind a web browser with a tiling UI.