My comment about kernel level programming was in reference to data acquisition products by companies like Keithly metrabyte, Computer Boards Incorporated, IOTech, National Instruments, etc, who produce plug-in acquisition boards. These lead you to reading documents like
this (although IOTech has a Parallel Port or PCMCIA solution module that will do on the order of 1 million samples per second aggregate, but it streams to ram, YMMV). The drivers for this one were particularly interesting.
I'd be interested to see some of the IO Work that you've done in Win32::RawIO. I was looking at a site earlier that had a large section on USB development for linux (though nothing specific to data acquisition)...The possibilities are endless.
C-.