Ever since I got my Proxmark3 tool I wanted to make it portable. Of course, Proxmark3 has a standalone mode which means you can power it off of a USB powerbank and operate it with its single button. This option is obviously limited and I wanted to be able to do more.
On the other hand, I have a good old Nokia n900. The two seemed like a perfect pair. N900 doesn’t support usb host mode out of the box, but latest firmware from the awesome maemo community and a couple of modules and tools does allow for n900 to act as a USB host. To enable the host mode, you’d need to install H-E=N or host mode enabler GUI (the package is called hostmode-gui) which will in turn install kernel-power (so be careful unless you already have it).