I have nothing against Norway, and I wouldn't mind learning Norsk once our neo-viking overlords rule the world, it's just another Indo-European language after all. Until the time that most of the world population (or at least the EEs) have learned Norsk, however, I suggest that communicating in English is the most effective for an international audience. One common language is the most effective on a global forum like this, didn't we learn anything from Babel?
On topic:
Interfacing with a bus pirate, like joelby suggests, would be quite easy, since it's just an async serial (like RS-232) connection plus an FT-232 to convert it to USB. There wouldn't be much point, however, might as well implement whatever protocol you need directly. The Bus Pirate is a very versatile swiss-army knife of slow serial protocols. It's not particularly good at anything in particular, transfer speeds are limited, for example, but it's very useful for quick and dirty jobs. This versatility and design for interactive use basically requires a keyboard, in my opinion, and does not lend itself very well to a few dedicated buttons.
Same for most SPI/I2C host devices, since they are designed to send and receive streams of data. Where are you going to put this data or get this data from in a piece of stand-alone equipment, unless it incorporates almost a complete PC?