provides you with a really easy solution for PDF on Mac
PDF Compress for Mac Expert
PDF Compress for Mac is a Mac OS X utility for reducing the size of PDF files, which compresses PDF file size by optimizing the resolution and compression method of images, removing unused thumbnails and metadata, stripping dead-object and compressing other parts of PDF files. Just drop your file on the panel and it will quickly create a new, compressed PDF file suitable for sending via e-mail or posting on the Web.
Rich choices of compression options.
PDF documents compressed to the file size you need.