Barry914 shared his oversized MintyBoost project in the Adafruit Forums:
I used your PowerBoost 500 Basic to make an oversized portable charger. I mounted it in an Altoids mint box which gave me enough room to use a 3-cell AAA holder and space to store a short USB cable, too. I drilled a hole near the USB connector and glued a piece of acrylic to the side of the USB connector to act as a light pipe so the power LED is visible with the case closed. It’s a lot bigger than the MintyBoost, but for me being able to store the cable inside is a plus.
Featured Adafruit Product!
MintyBoost Kit: The world’s first and only open-source hardware charger: The MintyBoost®! New version! Works with the new iPhone 4 & 5 and more! Please review the Minty Boost project page(s) before purchase and assembly!, some phones require different modifications to the kit to charge properly! Some phones such as the *iPhone 3gs are very sensitive to charging via USB and may not work in all environments or configurations.
Make your own iPod/iPhone/GPS/etc… battery-pack and recharger! This project includes all the electronic parts necessary to build your own MintyBoost: a small & simple (but very powerful) USB charger for your iPod (or other mp3 player), camera, cell phone, and any other gadget you can plug into a USB port to charge. The charger circuitry and 2 AA batteries fit into an small space such as an Altoids gum or mint tin, and will run your iPod for hours, 2.5x more than you’d get from a 9V USB charger! You can use rechargeable batteries too. (read more)