Imposition Wizard

Imposition Wizard is a standalone application for Mac OS X that does imposing. It doesn't need any third-party software, just reads PDF file, imposes it and save to another PDF file. All standard impositions supported: booklet, n-up, step and repeat, cut stack. Various options: creeps, bleeds, cropping, padding, page and sheet reordering and much more. All features are packed to easy to use interface. One of the most important feature is that your changes are visible in real time, forget about wizards with many steps where you see results at the end. With Imposition Wizard you will see every change immediately.

Limitations:

Watermark on saved PDF files