Laptops have long been replacing desktop models as primary machines for many households, with many of us laptop users used to docking our machines to a keyboard, mouse, and external model setup while at home(base). I currently keep my machine on a stand, since I like to use the laptop screen as a secondary display for instant messaging and other notifications. But I've also considered shutting the lid and storing my machine vertically for the benefit of more desk area...
Constructed from a single piece of high-grade aluminum with various plastic inserts included, the AluBase ($49.95) is designed to accommodate for the MacBook Pro, MacBook Pro with Retina display and MacBook Air in a secure position. The relatively small size doesn't visually or physically clutter the desk, but its low mass should keep machines securely in place while "docked". This is basically a less stylized, minimalist rendition of the similarly priced TwelveSouth BookArc (it may just come down to the issue of whether you like a more puck-ish design versus the arc).
I personally love this design even more than the vertical stand because I only move my laptop for the (unfortunately) rare occasion I'm traveling for work. The hideaway design makes use of the larger screen of the 27" iMac or Thunderbolt Display to disguise the laptop's presence behind a display, all the while keeping connected to the screen through the stand's porthole. I think I may have found a reason to commit to one screen rather than two...or at least give it a fair shake.
Other Laptop Stand Accessory Storage Options:
The TwelveSouth Book Arc is priced similarly to the AluBase.
BackPack hooks to the rear of iMacs or Apple Displays in similar fashion to the AluRack, except the small shelf is designed to hold an external hard drive or other smaller component.
Then there's always the $1.99 DIY IKEA Vertical Laptop Stand solution if you don't need the matching aluminum finish and need a project to plaster all those extra Apple logo stickers on.