Playlist Blender 1.2 for Mac is free to download from our application library. The application is included in Audio & Video Tools.
From the developer:
Playlist Blender allows users to easily manage iTunes random playlists in new ways. Combine playlists in proportions you set; create master playlists in desired sizes (great for mp3 collections that exceed the capacity of your iPod); update your master playlists with one button; instantly recall your favorite mixes. It makes smart playlists even smarter. Trial version good for 15 days.
You may want to check out more software for Mac, such as Blend, Photo Blender or Color Blender, which might be related to Playlist Blender.