1.) that would either require it be on-line (then not on an indivual basis...but EVERYONE)
2.) I believe this is supposed to be for off-line demo., but would still need internet access then to have the 'time check'
3.) no matter wat you do..they can mess with the SO and edit the values if they know how.

the BEST would be using a combination of all of them...current time, SO & server time checking... but again..nothing is fool proof.

oh, and psssssst ....(this thread is like 5 months old)