I am currently working on the authentication of an AJAX based site, and was wondering if anybody had any reccomendations on best practices for this sort of thing.
My
Your best bet is using an SSL connection over a previously authenticated connection with something Apache and/or Tomcat. Form based authentication in either one, with a required SSL connection gives you a secure connection. The webapp can then provide security and identity for the session and the client side Ajax doesn't need to be concerned with security.