If you’re looking for a slick Ajax file upload method, Fancy Upload is it.

From the site: “Swiff meets Ajax for powerful and elegant uploads. FancyUpload is a file-input replacement which features an unobtrusive, multiple-file selection menu and queued upload with an animated progress bar. It is easy to setup, is server independent, completely styleable via CSS and XHTML and uses MooTools to work in all modern browsers.”