The plug-in to view Flash content can be downloaded from their page, but in order to create dynamic menus using Flash, you have to pay for the software. Check out an example of Flash at E3 Direktiv . It uses a standard imagemap style with the additional option of embedded sounds. It also allows for embedded sounds. Gamelan's Imagemap directory lists all current imagemap applets.
Dynamic documents are easy to use, and have been used to do some really amazing stuff.
Client Pull A client pull allows the server to tell the browser to load a certain document in a certain number of seconds. This document will reload itself once every second. Some sites use this type of client pull to refresh a document such as stock quotes or a video camera pointed at a city street. Client pulls can also load a different document in a predefined number of seconds. This example will send you to Carl's home page in 5 seconds.