Menu with transparency

Hi all !

I'm new to web dev / jQuery, and despite my google searches I didn't find something concerning the menus : i'd like to have a nice "item-list-style" menu with a transparency effect on it, like you can see here : http://www.ipex.org/. Is there a way to do it with base-jQuery ? Or do I have to find a plugin ? If so, does anybody knows of it ?

Thank for your help and have a good day,
ack.