Application scope variables

[eluser]MarvinLeRouge[/eluser]
Hi,

I'd like to create application scope variables, so that any user of the application could have access to the same variables. Plus it would allow me to update those variables every time interval i choose, just one time for everyone : less sql queries, less computing, more speed.
It's for an ACL, and since the rights are already defined, and rarely changed, i just need to invalidate the data when there's change.

Any idea ?

Thanks