View source for Pancake/Retina Images for Web

  gbrander: Are we doing anything with the @2x images yet?
  st3fan: they are for the iPhone4 i think, but not sure if they actually get loaded

* [http://stackoverflow.com/questions/4949707/iphone-is-2x-valid-for-uiwebview Does UIWebView load in @2x images automatically]? Nope.
* Background images: [http://blog.iwalt.com/2010/06/targeting-the-iphone-4-retina-display-with-css3-media-queries.html Targeting Retina Display with @media] -- that's pretty easy.
* Real images: we have a few options...
** The easy hack: load in the @2x version for everyone and use @width to shrink by half.
** Responsive images:
*** This is a pretty shaky technique right now, with a lot of approaches and no clear winner https://docs.google.com/a/crowdfave.org/spreadsheet/ccc?key=0AisdYBkuKzZ9dHpzSmd6ZTdhbDdoN21YZ29WRVdlckE&hl=en_US#gid=0
*** Scott Jehl did a clever hack with canvas http://scottjehl.com/imgwithfallback.html
** Detect retina display with UIWebView and pipe to appropriate template (not very DRY)
** Create image with JavaScript, provide urls to both sizes and use JavaScript media queries to create the right one (this might make the most sense with the thumbnails).