I had developed a mashup web site using dojo.
Astray dotproject.
http://astraydot.com/srv/idx

Using dojox.gfx for dynamic scatter chart with events.
The site have simple 2 applications.

pororoca:Visualized amazon search
colloid:Yahoo vs Google. Search result comparator

Althogh it is natural, Ajax and dojox.gfx have high affinity.
I don't think Other visualization architecters without javascript (Flash, java applet...) could do that.