Method to update variable through hardware

I have Arduino Leonardo and every so and then I want to feed it new data to play with. The way I was initially considering was to plug a usb with formatted data in it and just tell it to read from usb and store it to local variable when I press a button.

But that is clearly not possible. I would like to know if there is any way to update 5 floats in the code while it is running without using computer to upload a new code.

If there is no way to feed in information, I would have to install a lot of buttons..

keypad, bluetooth, wifi, ethernet, rf?

How about a keypad?


Thank you all! Very helpful! Ill try keypad.