GNU usbsync is console-based utility that assists you in keeping files and entire directory trees synchronized between a portable storage volume (such as a USB flash or thumb drive) and arbitrarily many hosts. For this purpose, a special text file, usually named .usbsync, is placed in a storage volume's top-level directory to contain user-written synchronization entries.
Flashrom is a utility for reading, writing, erasing, and verifying flash ROM chips. It's often used to flash BIOS/coreboot/firmware/EFI images. It supports a wide range of DIP32, PLCC32, DIP8, SO8/SOIC8, and TSOP32/40/48 chips, which use various protocols such as LPC, FWH, parallel flash, or SPI. The tool can be used to flash BIOS/firmware images, for example, be it proprietary BIOS images or coreboot (previously known as LinuxBIOS) images. It can also be used to read the current existing BIOS/firmware from a flash chip.
Libpuppy is a library version of the puppy tool, which is used for accessing Topfield DVB tuners (and possibly others) via their USB port. Its main features are listing and retrieving contents of the HD in the device. It allows you to write your own utilities that interface with the device. It comes with two tools, puppy-dir and puppy-get, in addition to the original (mostly unmodified) puppy-tool.
ccid-utils is a USB smartcard driver and development platform. The driver follows a simple synchronous design that supports multiple slots but only one transaction at a time and includes a Python interface. It also includes a command line smartcard shell with a searchable history. The shell, written in Python, offers many useful features for developing with smart-cards and for reverse engineering APDU formats. It includes tools for reading data from GSM SIM cards and EMV credit/debit cards. The SIM tool is very basic, but allows reading SMS messages from the SIM. An example EMV (credit/debit) card tool is included that is boilerplate code for utilizing the EMV C API. There is also a Python interface for the EMV API. A graphical interface for reading EMV cards is provided.
g13 is a Linux-only library to interact with the Logitech G13 driver. This library provides several sublibraries including libg13, libg13mm, libg13-cairo, libg13-gtk, and libg13-gtkmm. These libraries provide functions and classes for browsing G13 devices through udev, setting the backlight color, establishing keymaps, and drawing on the G13 framebuffer device.
Ejecter is a little tool that makes it possible to unmount external devices and eject CD-ROMs without having to right-click on the device icon (either on the desktop or in Nautilus). It sits in the background and shows an icon in the system tray when one or more peripherals are connected to your PC: once clicked, a window appears with the list of the devices (volume name and device type, and much clearer than the similar thing available on Windows) and the related eject button. Being written in Vala, it is translated into C code and then compiled. This means that it's lightweight and consumes little memory, does not require a full VM like Python, and has no strange requirements to run (just GLib/GTK).