title: Cocoa-Touch: use button or UIImage for clickable image?
body: <p>I'm building a iOS app which involves lots of photos displayed as rectangular areas on the screen. You can click on that area and see a bigger version of the photo. Kind of like those wallpaper apps, where you first see a grid layout of small wallpapers and then you can go in to see a bigger version.</p>
  
  <p>So, I'm wonder what's the pros/cons in terms of memory usage and scalability between setting them up as UIButton (w/ background) and UIImageView? </p>