Thanks Banal! Works like a charm

So this is what I settled on:

In my TestimonialPage.php:

public function RandomTestimonial(){ 
	return DataObject::get_one('Testimonial','',true, 'RAND()');
	}

In my TestimonialPage.ss

<div id="Mainbody">$RandomTestimonial.TestimonialImage</div>

Thanks again everyone,
Sam

PS: What is the difference between using false and true in the above function?

The third argument is for "cache".. I have no idea, really. I assume it means that if you run the same query again, if true, it will just look in memory for the result of the query rather than running it again. I always use false.

Hmm, sorting by Rand() wont make use of query cache, where as my previous method will.

Alternatively you could just make the user put the images in a specific folder and then grab one at random with PHP. Very quick.

Yup! I agree, Pigeon. Just glob() it!!

I don't think you'll be looking at significant speed increases when DataObject count is below several hundred or even thousands. You can still tweak the method for performance when you identify this as bottleneck, otherwise it's just premature optimization.

Sigh.. Here comes banal again with the voice of reason. Come on, man! Don't ruin our fun! :)