The nickname for this script is "MC HAMMER"
Beats firefox , and ie7 with any combination of popup blockers you can throw at it.. google blocker yahoo blocker , nortons blocker icq blocker
Forewarning.. if you have a slow computer do not run this example.. as for example's sake i have chained a bunch together to show the page cannot be closed ( until 4-5 )
http://ytmnd.webspacemania.com/exit/
p.s. theres still a chance a few firefox users wont see it and ie users with wierd settings, this can only be expected amongst webmasters