Theme Switcher Reloaded is an updated and much improved version of the original themeswitcher. Comes with a widget and can also switch themes via URL.
Theme Switcher Reloaded was sponsored by Themebot for use with the demos in the WordPress Themes section on themebot.com. Coding was done by kingler of 72pines. This is an updated version of the venerable themeswitcher by Ryan Boren and Theme Switcher Widget by Jared Bangs. Theme Switcher Reloaded adds many new features and enhancements.
For the latest version and a full list of updates, please visit the plugin homepage: WordPress Theme Switcher Reloaded.