The Raspberry Pi has been a terrific success. Despite minimal third-party software support and manufacturing delays, the system remains a best-seller, with buyers waiting weeks to receive their orders as production ramps to meet demand. But what is it exactly that people are doing with all these Pis?

For a (mildly) less impressive Raspberry Pi project you can do at home, why not check out our guide on how to turn a Raspberry Pi into an XBMC media center?

Want to buy a Raspberry Pi? Discover the full range of kits, accessories and cases here.

1. The Raspberry supercomputer

The Raspberry Pi itself is hardly the computational equal of the average desktop or laptop, yet some buyers have been investigating its suitability for high-performance computing – if only as an educational exercise. Professor Simon Cox of the University of Southampton, in partnership with fellow computational engineers and his six-year old son, recently unveiled the first large-scale supercomputer cluster constructed entirely from Raspberry Pi hardware.

“As soon as we were able to source sufficient Raspberry Pi computers, we wanted to see if it was possible to link them together into a supercomputer,” explains Cox. “We installed and built all of the necessary software on the Pi, starting from a standard Debian ‘Wheezy’ system image, and we’ve now published a guide so you can build your own supercomputer.”

At a cost of £2,500, the system boasts 64 nodes, 16GB of memory, 1TB of SD card storage and a Lego chassis. While its performance lags behind traditional supercomputers, Cox’s creation provides a low-cost platform for experimenting with computing cluster technology – something that normally requires a hefty server environment and software simulation. Details of the build are available at the project’s website, along with a guide for constructing a similar Pi cluster.

2. Translation goggles

Wearable computing has been “just around the corner” for decades now, but beyond the odd bulky wristwatch, little usable technology has hit the open market. Google’s Project Glass is due to appear in shops some time next year, but for now the Pi is helping to fill the gap thanks to its small size, light weight and low power draw — so low, in fact, it’ll run for hours from a cheap lithium-ion battery.

The most impressive wearable Pi effort so far has to be Will Powell’s project which turns two Raspberry Pi systems and a pair of off-the-shelf digital glasses into the closest thing the world has seen to the universal translator of Star Trek fame. Combining a Vuzix 1200 Star wearable display and a Jawbone Bluetooth microphone Pi, the system performs on-the-fly voice recognition and translation through Microsoft’s publicly-accessible application programming interface (API.)

“I can have a conversation with Elizabeth, who speaks Spanish to me, and I return with English,” explains Powell. “I have never learnt Spanish, but using the glasses I can have a full conversation.”

Details of the build including a video of the system in action, are available on Powell’s blog.

3. Marine robotics with the Fish Pi

The general-purpose input-output (GPIO) port on the Pi provides an easy means of interfacing with external hardware, and for many technical types that spells “robotics”. Several small-scale projects have seen the Pi mated to off-the-shelf remote-control cars and the like, but the Fish Pi project goes a step further in its aims.

The brainchild of Greg Holloway, Fish Pi looks to create a fully-autonomous marine surface vehicle capable of crossing the Atlantic Ocean without human intervention. As well as making heavy use of the Raspberry Pi’s inter-integrated circuit (I²C) connectivity for the electronic speed controller, servo controller, GPS and electronic compass, the Fish Pi takes advantage of the Pi’s low power draw in order to run the entire system from a solar panel.