Apple's Automator app is quite good at this. I like it for making little one-off droplets, so you can drag a bunch of files onto it and process the batch. It's

Apple's Automator app is quite good at this. I like it for making little one-off droplets, so you can drag a bunch of files onto it and process the batch. It's still not quite as powerful as doing things at the command line. It does interface better with the OS and lets you write quick graphical apps.