Mac only: We recently featured a multiple file type converter for Windows, but now Mac users can share in that same drag-and-drop joy with Dragoman, a free app that can batch convert images, photos, music, documents and archives with minimal effort.
Dragoman could not be more simple to use: All you do is drag one or more files into its window, choose a compatible file type for the output, and wait for it to pop out your shiny new files. It can convert tons of different file types, too, like images (including many RAW formats), music, documents and even archives — useful if you start using a different camera or program that can't open a certain type of file (like Apple's TIFF or Webarchive formats). It can also convert multiple files at once — even if your original batch contains files of more than one type, you can convert them all at once to one. In addition, if applicable, you can edit image preferences like JPEG quality and DPI for your converted files. If you're still not convinced, be sure to check out the full list of supported file types — it's nothing to sneeze at.
Dragoman is a free download, Mac only.