[Daniel Daigle] is developing a rotary display that uses persistence of vision to graph data. The hardware he used includes a spinning head from a VCR, some LEDs, and a timing circuit to display 360 degrees of data. His timing input uses a waveform so this will work with any application where you can generate a PWM signal.
Check out his videos after the break that demonstrate a graph with a single line and another with six display lines.
Single line rotary display
Six line rotary display