The online lab I've been using (happily) is Mpix. Their instructions for submitting non-standard aspect ratio images is to “place them on a canvas in Photoshop” and size to the next highest size. Basically, creating a border around the image to allow the “canvas” to match a standard print size. I'm holding out against purchasing PhotoShop (Aperture does 95% of what I need and $700 is a lot to spend on software). Questions: Is there a way to create the “larger canvas” that is required using Aperture?
This was an incredible conversation, covering virtualizing trade shows, remote post production, and how to replace the social benefit of human gatherings.