a cool feature for ipb

ok this is my idea as i have seen it on loads of other makes of boards:

member (any) logins into site, a pop up or something is in front of the user saying " the board owner needs you to view a topic/post " please click here

you are then taken to the topic / post and the user will read, and confrim by ticking a box or hitting a button to confirm is done!

I have seen this on a few boards, i think are php boards, but i think this is a great idea, as can be used for loads of things.

for me i want to use it for the following:

to make sure email addresses are upto date as so far i have 200 out of 2000 members showing as dead so can ask people to confirm emails
to make sure people fill out some profile details
as my site is about cars, want to point people to maybe new car shows or events
also to update people about new rules ect for board?

let me know your ideas?

im guessing one problem could be cookies? if some one cleaned them would it save on the database as confirmed reading?