Often, while using an iPad or smartphone, I want to multi-task. I don’t mean ‘fast app switching’ or running something in the background, I mean I want to see two applications at one time. That’s not possible with today’s smartphones, so I’ve been experimenting with using two devices at once. 2 screens = 2 apps.

In many settings, this kind of experience is easy. Sitting at a table, you can prop up one device and hold the other in your hands. In other settings, it’s very difficult. On a train, in a comfy chair, in bed, it’s difficult to use 2 smartphones or other multimedia devices simultaneously.

To solve that problem, I’ve tried a number of solutions to fix two or more devices together. I’ve focused on non-permanent techniques, since on device is always my phone and I need to be able to carry that alone.

Attempt 1: Use Shapelock (a plastic substance that melts and re-hardens easily and can be molded by hand) to create a case that holds two devices. That was not successful at all. The Shapelock is just too hard to coax into the desired shape.

Attempt 2: Velcro devices to a metal ruler. This works extremely well. The devices can be rotated to any orientation and the ruler can be bent to put the devices at an angle to one another. Unfortunately, the velcro gets gummy and dirty quickly.

Attempt 3: Combine rubber bands, a small clipboard and those grippy dashboard pads to hold multiple devices in place against a plastic plate (the clipboard). Too complicated. I used it twice, but it was difficult to get the devices situated.

Attempt 4: 3D printed clips that connect two or more devices. I modelled these in Google SketchUp and had a little trouble getting the fit right. The first batch of these that have the right dimensions to grip my iPhone 4, iPad and Droid X correctly just arrived today. I have several more clips coming from Shapeways over the next week or so. It’s too early to say if this approach will be successful, but there are a lot of reasons to believe it will be. The clips are small – they are pocketable. The clips grip well enough to feel confident that nothing will fall (except for the iPad clip-it needs to be a little tighter) if I’m reasonably careful. The clips are modular. Though I have to order a new clip for each device (each device has a different thickness), they aren’t very expensive. The nature of the clips makes it possible to have extenders or angled connectors to get exactly the orientations you are looking for.

In a few weeks, once I have the dimensions cleaned up a bit, I’ll post the final models you can use for printing – at your own risk, of course. If you desperately want the models AS-IS to make your own prints before I’ve had a chance to refine them, let me know in the comments and I’ll send you the files.

Below are a few photos. First, the clips themselves, alone. They look like Tron Recognizers… Second, 2 pieces holding an iPhone 4 and iPad together. Third, a Droid X and an iPhone 4. The multitasking shots are a little contrived (researching Star Trek while watching it; reading techmeme while watching a movie). The more likely use cases involve email, feeds (MobileRSS!!), Twitter, etc. The last picture shows several more clips and adapters that haven’t arrived, yet.

[If 3D printed iphone accessories are your cup of tea, also check out the Glif (although the Glif is now injection molded).]