I'm a sucker for a good Kickstarter project. I'm also a big fan of anything involving low-budget movie-making. That's why I'm jazzed about CineSkates, which combines a GorillaPod tripod and three inline skates to create a smooth-rolling camera mount.
Although this soon-to-ship product isn't expressly designed for the iPhone, it can certainly work with one--so long as you pair it with an iPhone tripod-mount case like the Canopy Kapok.
CineSkates comes with three skates designed to attach to a GorillaPod Focus tripod. You can supply your own, or buy one as part of your Kickstarter pledge. (Inventor Justin Jensen plans to make CineSkates compatible with other tripods down the road.)
I can blather all day about how cool this thing is, but it won't compare with what you'll see in the pitch video:
If you're going to BYO GorillaPod and BallHead X, you can buy into a set of CineSkates for $150. At the $275 pledge level you get everything: CineSkates, GorillaPod Focus, and BallHead X. Once the Kickstarter project ends, retail prices for these will be around $200 and $300, respectively.
That may seem a little steep, but it's spare change compared with what you might pay for similar pro-level gear. If you're a moviemaker looking to capture cool-looking low-angle and/or dolly shots on the cheap, CineSkates might be just the solution you need.