If your Rails app uses Rmagick to resize images on shared hosting you may have had your app shut down because of a RAM spikes (the spike can be > 40mb when processing an image > 2mb).
MiniMagick to the rescue!
MiniMagick accesses ImageMagick directly, similar to exec(’my ImageMagick command’); in PHP. Since shared hosts are looking for Rails spikes not ImageMagick spikes your app won’t get killed. If you use Rick Olson’s excellent attachement_fu plug-in MiniMagick support is baked right in.