System Screensavers Tweaker is a freeware portable app which allows you to tweak and change settings of Bubbles, Mystify, Ribbons, Lines and Aurora (excluded from 7 by default) screen savers.
System Screensavers Tweaker
The application supports x86 and x64 versions of Windows Vista and Windows 7.
It also supports ported versions of that screen-savers under Windows XP. It supports English & Russian languages.
Download : Home Page.
Requires .Net Framework 3.5.