Apple - How do I Convert FLAC files to ALAC for iTunes?

Have a look at Max. Freeware and Open source. Has a GUI.

I'm a fan of XLD and since the original question was posed it gained the drag-and-drop folder capabilities that the person asking the question as after. No need to install Growl to get it to work. It also handles embedded images in FLAC files when doing the conversion and will keep them in the ALAC output files.