I used to have a modem that was a little black cube about 1.25" on each side. Maybe a little bigger. 19.2Kbaud I think. I can't remember the name of the company or the model or anything and searches haven't found anything. Does anyone remember this one?
It was a really strange form factor - especially considering most modems of the time were just in extruded aluminum cases of one kind or another. For some reason I've been thinking of it lately.