I guess I've got Opalescence.. the kind that only takes 30 minutes. I could really see a difference after the first day (I did 4 days before my trip) so I'm pretty psyched to keep going! I think my teeth were really yellow though. And the half hour doesn't seem too long if I have something to do.

I sympathize though, because it did feel daunting to start, and mine sat around for a couple of months also for that reason.