Donncha O Caoimh (a11n)

This plugin allows a blog administrator to test a new theme while showing the old theme to regular visitors.

Theme Tester

Test a theme on your blog without showing your visitors

Federico Jacobi

Helps you use a different theme depending on the browser your site is viewed on. This is great for things like having a dedicated theme for mobile devices, but also is a great way to cheat your way out of CSS hacks and browser specific annoyances ( IE anybody? ). Even though themes are usually designed to be cross browser and CSS fine tuning is part of it, sometimes you do not have the time to spend trying to figure out a way to make the pages behave across browsers.
PLEASE vote and/or rate if it works for you or let me know if there’s a fix needed at web[at]federicojacobi.com.
Supported browsers for now: Internet Explorer, FireFox, Chrome, Opera, iPad/iPhone/iPod, Safari, Playstation 3, and BlackBerries.
Thanks to Drazen Mokic, Nicholas McQuillin and Paul Gregory for their help and suggestions.

Theme to Browser (T2B) Control

Displays different themes based on the browser used.

Theme Tester vs Theme to Browser (T2B) Control