Like the robot Number 5 from Short Circut, the keyboard glove will need more than the handful of GPIO pins that the trinket provides. About 30 in total.

Shift Registers

Now, how do you get more pins on an Arduino? With a SN74HC165N of course!

What is a SN74HC165N you ask? It is a kind of shift register. It converts 8 parallel inputs into a series of pulses which can be read by the Trinket. Even better, you can chain these babies together to read even more inputs!

Now, I warned everyone that I am new to hardware design, and this is a great example. I picked out the parallel-to-serial converter without realizing that all those inputs would need pull-up resistors. Thirty-odd resistors will end up eating a lot more power than using a serial-to-parallel converter. Oh well, this is a learning experience, right?

Here's a picture of me trying out the SN74HC165N: