When I looked in the Joomla!™ extensions directory for a testimonial rotator I couldn't find one that met my needs. Some come with bulky components which is beyond my requirement, while others are just too simple and don't have enough "slots" to place additional quotes.
This one attempts to remedy these drawbacks, and others:
There are 15 slots available for testimonials / quotes. This may seem like a lot, but....
There is a randomisation option which when enabled will randomise the order the quotes are displayed in. This results in your users seeing more quotes as they navigate your site!
There is a field to optionally place the quote author
You can set the timings of how long the quotes are displayed, and time taken for the transition (this is a feature of Sebastian's code)
In conjunction with the randomise option, you can choose to only display one random quote per page load. Ideal when you you want the user to concentrate on completing a process. (e.g. Filling out a form or completing a purchase.) but don't want them distracted by animation occurring on the page