USB support is an OS level problem. Preliminary USB support is available in the 2.4 linux kernel, and some BSD's.

If you're really interested in Linux USB, see this site. However, I don't think your question is very relevant to Perl itself. I am not familiar with the Linux USB interface, but I assume it's accessible through character devices. If that's the case, you should be able to use Perl's file i/o to communicate with the device. The rest is up to you.