Marc Moini has released a new app for Mac users, Smart Scroll 1.0. Smart Scroll is a utility designed for adding scroll functions to the OS X interface. The update addresses some bug issues and improves Panther support. According to Marc Moini:
Following in the steps of the classic Smart Scroll, Smart Scroll X brings essential user interface enhancements to Mac OS X.
Version 1.1b1 fixes a number of issues with last weekis 1.0 version, and adds support for Mac OS 10.3 Panther.
You can find more information about the Smart Scroll update at the Marc Moini Web site. The Smart Scroll update is free for registered users, while the full version is available for US$15.00.