session variable

Is there way to set and check user session variables with the Rules module? I know I could this with custom php but I am wondering if there is built in way to this with Rules or a contrib module.

I basically want a boolean session flag. This will allow me to perform some action the first time a user views a page(or does something else).

My idea would be:

Condition:
Check session flag(or variable)

Action:
Set Session flag(or variable)

Any ideas?

Thanks