These were even faster for a large number of elements: (0..99999).to_a.shuffle[0..4], (0..99999).sort_by{rand}[0..4]. (Than this: (0..99999).to_a.sort{rand() -0.5 }[0..4].)

Woot! QuickCal ftw! Thanks, Brett!

Thanks for all the interest, folks. There's a 14 day trial on our website you can hit if you want to check it out..

Congrats to those who won... Shame I wasn't one of them.

Keep these promos coming though ;)