Ajax examples...

these 2 are cool examples of AJAX...

• Amazon Diamond Search slider search http://www.amazon.com/gp/search/finder/?productGroupID=loose%5fdiamonds
• Rico - Ajax platformhttp://www.openrico.org/

this one....you'll see how relevant this is... Protopage virtual note taking space for stickies/post-its http://www.protopage.com/

Other Examples:-
Jamesdam.com
login without page refresh or submit button
http://www.jamesdam.com/ajax_login/login.html
Ajax Periodic table of the elements
zoom in
http://code.jalenack.com/periodic/
Del.icio.us Direc.tor
alternate interface to del.icio.us
browse your tags
http://johnvey.com/features/deliciousdirector/
See also -Making Ajax faster