using more than 1 javascript library

i am playing with various javascript tools, such as slideshows and carousels and which invariably use different libraries, such as mootols, jquery and yui.

I presume it's not a particularly good idea to mix & match, but wonder if its possible to use 2 different libraries on the same page.

I'm currently developing my site, and have a header which is based on slideshow 2, (mootools) which loops through a series of still images to give me (imho) a nice effect.

www.stonepits.com

I am currently looking at javascript carousels, ideally for one where i can have text and images, which provide links to external content.
After playing with jcarousel for a couple of days, i think the yui carousel is more powerful, and have got something working, (not finished, but working)
The problem is that i cant get both to work on the same page.

yuicarousel.php

Is it a case of loading the libraries in the correct order, or is the problem more fuindamental ?

If i am hitting a wall, can someone please recommend a good yui based tool to act like slideshow ?

regards