Hello guys,
Swift-Switch is a script that can change render engines instantly and features V-Ray Presets and Mental-Ray Presets. It also features many more interesting stuffs like Global Ambient Occlusion, Save/Load Presets, Optimize Final Gather, 2012 Viewport Settings, Mini Rendering and more.
You can also control V-Ray Core elements from the script itself. The latest version also features M-Converter (Material Converter [BETA]) and unique VRay OceanMtl.
Here is a screenshot of Swift-Switch.

Screenshot of VRay OceanMtl:

Screenshot of M-Converter:

This Script is FREE to use 
Download:
http://swift-switch.co.cc/
Visit Blog for latest news and more screenshots :bounce:
http://swiftswitch.blogspot.com/
I really hope you all like it. If you found any bug please send it to: feedback@swift-switch.co.cc
Feedback and comments are really appreciated 