GUI controls for instrumentation

[Kenneth Porter]

I'm tasked to write a front end for an instrumentation application for 
"that other operating system" ;) and I'd like to use GUI controls that are 
cross-platform portable for an eventual Linux port. What would the list 
recommend? I essentially need something that resembles the front panel of 
an oscilloscope, along with some dial indicators and knobs. I've also been 
thinking about making it web-accessible, so perhaps a Java-based solution 
would be suitable.