Every now and then, an iPhone application hits the marketplace and causes an absolute stir. Gym Babes is one of them.It is, quite simply, one of the most innovative concepts I’ve ever seen. It's patently useless. It won't tell you the time in Tokyo.It won't find your last train home. It won't pay the London Congestion Charge automatically according to your location.It won't let you book a hotel room.It won't enable you to converse with a Mongolian Monk about the next moon cycle. But.And there is a but!It will let you watch a choice of two reasonably attractive women running on a treadmill, formatted in glorious iPhone format.What's more you get a choice of whether you'd like to see the lady run, walk or 'slow-mo'. And there is, of course, some fairly dodgy — yet highly appropriate -- accompanying music. Why is this good? Why is this the pinnacle?Well, the concept. It's simply marvelous. How simple can you get? Run the application, select a girl (there's a choice of two at the moment) and you see a perfectly formatted close-up portrait video of that girl running, along with the dodgy music. It does what it says on the tin.Then there's the innovation. Somebody at Vertex, the developers, came up with the concept. They got out their cash, hired some developers, took the time to film the movies in high quality and format them correctly for the iPhone experience, and they sent the app out to the marketplace. I love what this says about entrepreneurial possibilities in the iPhone App Era.It was so simple for them that I bet they were able to create the whole thing, including videos, for a few thousand dollars.The barriers to entry are so low that this concept was able to be turned from idea to reality. I also really, really like the fact that this does not exist for the Nokia Ovi Store. I like this, because it's a con