As noted, one of the interesting features is the ability to project an image on a ceiling by titling the front of the projector straight up at a right angle. This doesn't work well at all if you have tall ceilings, but those with shorter ceiling (less than 8 feet high), might find it alluring. The picture isn't great, but chances are, it will be a big hit with your kids and their friends. You should just be aware that the tiny integrated speaker isn't terribly loud, so you need to sit near the projector to hear the soundtrack of a movie (you can attach external speakers or connect headphones if you want better sound). It's also worth noting that though the projector runs quietly, it does get a little warm at the front.
We've seen a few other pico projectors in action and the image quality, particularly in terms of brightness, is similar for all of them (this model's rated at 8 lumens). For comparison, we put the Cinemin up against the 3M MPro120, which costs about the same (right around $300, albeit with the iPod cable), but has higher resolution (640x480 pixels), better battery life (4 hours versus the Cinemin's 2), and brightness levels (it's rated at 12 lumens in its "high" setting).
That said, we found the Cinemin's picture to be slightly better than the 3M's, with slightly deeper blacks (the Cinemin uses DLP technology versus the 3M's LCoS). The MPro's picture was a tad sharper but we liked the color better on the Cinemin. It's also worth noting that to get the picture to display correctly we had to set our iPhone to display in wide screen for the Cinemin and 4:3 for the MPro 120.
We weren't incredibly impressed with either projector, but we think WowWee has done a better job making this more consumer friendly, particularly with the inclusion of the Apple adapter and swivel mechanism. Ultimately, at this stage, pico projectors make some sense for parents and business travelers who want to watch an iPhone/iPod movie on a screen that's larger than their laptop's screen, though the prices put the units beyond the impulse purchase category.
In short, yes, there's something cool about the concept of carrying around a tiny, portable projector, and creating a mini instant theater. But just keep your expectations low as far as picture and sound quality--and make sure to watch in a darkened room--and you'll probably be happy with the Cinemin Swivel. But as we said in our review of the 3M MPro120, the technology is advancing and we expect that next-generation models will offer improved performance and (ideally) lower prices.