Hold down the option key. Hover your mouse pointer over the green zoom button in the top-left corner of the window. A "move window to the left/right side of the screen" option appears.
It sort of does, but it's not as obvious as it should be. Mouse over the green zoom button in the top-left corner of a window, hold the option key on your keyboard, and then "move window left" and "move window right" options appear.
My employer tried and failed using a similar system with Salesforce Work.com. It all seemed a bit pointless and forced to me. In the early days of using it while it was still a novelty, managers were giving feedback to people so that they could demonstrate to HR that they were being good little soldiers by using the tool, rather than because they wanted to praise good performance. This insincere praise was worse than no feedback at all.
In the end, it never really went anywhere because it became another inbox to check, and we already have too many of those. A chicken-and-egg problem also presented itself, where people only checked the site when they got a notification saying they'd received feedback, which led to no-one visiting the site to give feedback.