Wordpress Plugin/Widget For Changing Theme?

I've seen on other peoples' Wordpress blogs, they have an option where the user can change the theme they are viewing it on by the click of a link.

As my blog is for selling wordpress templates, it would be very helpful if i could install this plugin etc.

Anyone know where i can find it?

 

I think that http://dev.wp-plugins.org/wiki/ThemeSwitcher is what will help you out.

 

That's exactly what i meant. Thanks very much!