Not that I care about a light that tells me if I have e-mail pending. But controling pretty lights from the computer? I'm all over that. Someone had already written a script in Python to control these things. I ported it to Perl because, well because I like Perl.
To use it, you must have Device::USB installed. And perl, of course.
Doing setcolour will show you all devices installed
Doing setcolour 1294:1320 1 will set all mail devices to colour 1, which is blue on one of my devices, green on the other.
Doing setcolour 2-7 2 will set one mail device to colour 2, which is red on both my devices.