Javascript carousels are used to display some images or content, in a often narrow space, allowing the webdesigner to show much info in a limited space. They add some functionality to page, and in the same time some visual candy.
Some of scripts that can help us to achieve this are presented below:
Carousel Component

The script use YUI and has a nice list of features like vertical/horizontal mode, ajax fetch for content,animation control and works with most of modern browsers
iCarousel

The iCarouel script has as base mootools framework, and works on ie,frefox,opera and safari. We tested the script in konqueror and works fine too. It is pretty configurable, but require to tune the declaration of class for this (maybe a little hard for noobs).
Carousel Slideshow

The script supports vertical and horizontal scrolling, optional linking, title attributes, configurable visible sides, and more.
Simple 3D Carousel using Mootools

As the name says, is a simple 3d mimic carousel, based on mootools.The site explain how to implement the script.
jCarousel

jCarousel is a jQuery plugin for controlling a list of items in horizontal or vertical order. The items, which can be static HTML content or loaded with (or without) AJAX, can be scrolled back and forth (with or without animation).
Prototype Carousel w/ Scriptaculous (version 2)

This script is a prototype based carousel that allows for n-item paging. It utilize the scriptaculous effects library for carousel paging/movement. Additionally, the items within the carousel are extracted from the HTML itself so that they can be indexed in search engines.
ScrollShow

ScrollShow is a very customizable slideshow, that relies on jQuery.ScrollTo, to slide(scroll) the items.
Let me know for other scripts is same category.