How can you turn a small sample into a never-ending pad?

[Dave S]

Hey Bar,

Something has been puzzling me for a few days, and I wondered if anyone 
here knows the technique that might have been used, because I'd like to 
play around with it myself.

In December, I downloaded some free sample packs from Tonehammer (under 
the name "Gnomehammer") - one of which was called "Holy Ambience".

In the Holy Ambience pack, they appear to have taken a very small 
section of a sample, and manipulated it into huge, evolving atmospheric 
pads that seem to go on forever.

I'm wondering how this can be done?

I'm thinking perhaps it is convolution with a really long (probably 
artificially generated) reverb impulse.  Or maybe it was through a 
resynthesizer like Camel Audio's "Alchemy" or the Hartmann Neuron.

Anyone got any ideas?  I really want to play around with this technique, 
if I can figure out where to begin.

I'm kinda hoping it wasn't the resynthesis method, because I don't 
currently have access to that kind of thing - unless anyone knows a 
freebie VSTi or other free software that's capable of doing it?

Cheers for any pointers in the right direction!

~Dave