Theme Switcher
By Ryan Boren (http://ryan.boren.me/)
Why it's awesome: Users can customize your blog to their style
Why it was picked: Dead simple installation, giving visitors a custom experience
License: GNU General Public License
Manual Install URL: http://wordpress.org/extend/plugins/theme-switcher/
Automatic Install search term: Theme Switcher
Geek level: Newbie
Configuration location: Appearance | Widgets
Used in: Widgets, site-wide
Theme Switcher allows your readers to select available themes from your sites. Once selected, each time the visitor returns, they will be treated to the custom theme they picked.
Once installed, you will have a new Theme Switcher Widget to select from Appearance | Widgets. This widget allows you to display the available themes either as a List or a Drop-down Menu.
Advanced marketing use
If you're a company that markets to multiple channels/markets, Theme Switcher could easily be transformed into a Select Your Market, where each market/channel is...