These are 2 ideas that I have just heard on a presentation. To gain performance with your application, save the requests (dont worry much with pageload) and use a signed cookie to autenticate uses instead of checking the sessions.
The save the requests concept is pretty simple: If you browser already cached something, unless you really need to reload that file, save that request and let it cached. For example, don’t change an image name or add an identifier to a css file unless strictly needed. That will save a request, therefore gaining performance.
The signed cookie is an interesting concept. If you take a look, the read time to the database (or cache mechanism) to check if the use is authenticated is greater than your application checking for a signed cookie. Read the cookie and if is there, authenticate the user.
I really did like these 2 ideas and probably will start using them on my apps. Anyway, sharing the tip.