USB button

[Fernando Cassia]

Is there a dirt-cheap usb GPIO that I can plug in a USB port on Linux
and with minimal C code (or even bash) detect such button press and
trigger some action?

Im looking for a single digital input... I know there are some hacks
like disassembling a dirtcheap usb keyboard, but I wonder if theres
some device for embedded use that people on this list might have some
experience with...

TIA for any ideas
FC

-- 
During times of Universal Deceit, telling the truth becomes a revolutionary act
Durante épocas de Engaño Universal, decir la verdad se convierte en un
Acto Revolucionario
- George Orwell