+1 anecdotal to Flux.

I went all kindle | paper in bed (no more backlit things), and simultaneously also started using Flux, and it seems to have helped me actually stop working and fall sleep.

You get used to it in about three days, and then if you use the temporary-disable command to see what your monitor looked like before, it really does sear the eyes like when those nazis opened the ark...

I use flux as well. I still don't get tired at night (not if I'm working on something remotely interesting...), but it does seem to help me "settle down" a bit at night, so when I decide it's time to pack up for the day, I can often be asleep within 10 minutes (this used to be harder for me).

Pretty cool tool. This would not be as useful to someone doing design work that requires color accuracy though :-\.

It actually has a setting specifically to accommodate this. From their FAQ:

"f.lux was created by people who care a lot about accuracy in colors. We know you want to make sure your colors are perfect so there is an option to disable f.lux for 1 hour at a time (for example, while using Photoshop). This setting returns your screen to its normal settings. In the future we plan to allow automatic disabling of f.lux when you launch certain programs. f.lux is not designed for use during advanced color work, but it's fine for layout or HTML. Currently, we don't recommend running f.lux on calibrated systems running Windows, but we expect to have a solution for this soon."

Doing design work (or anything significantly intellectually stimulating) late at night isn't conducive to becoming a morning person.

Wow! This is amazing! I can't believe I never thought to look for something like this before.