Matt Gemmell: "iPhone developers are familiar with having to provide artwork at both regular and Retina (doubled) pixel dimensions for their apps. With rumours of a Retina Display-equipped iPad being just around the corner, it’s wise to consider moving to fully scaleable vector artwork for as much of your app’s images (such as toolbar icons) as possible."

Nice article for all iOS Developers. I'd imagine designers are already doing this, it makes sense. Vectors are a great starting point because you can usually scale them from large to small without much change. Yes, usually. I know designers with a pixel perfect eye that won't settle for less than perfect, but at least a vector can get you most of the way there before switching to pixel pushing.

The other thing to not in Matt's article is his use of a great utility from the fine folks at Panic; ShrinkIt. That tool is something every self respecting iOS developer and designer should have in their toolbox.