Ask any pro and they'll tell you that mixing using headphones isn't a very good idea. However, 112dB claims to have addressed the problems inherent to doing this and come up with a plug-in based solution.
It's called Redline Monitor and is described as a "high-quality near-field monitor simulation for headphones". 112dB states that it replaces the extreme stereo separation characteristic of headphones with the detailed stereo image of nearfield monitor speakers.
In theory, this should enable you to create an accurate listening environment in which to mix.
Redline Monitor sports just a few simple controls, and lets you switch the output to mono so you can check for compatibility. Sample rates of up to 384kHz are supported and there's MIDI learn.
The plug-in is Mac- and PC- compatible, supports the RTAS/AU and VST plug-in formats and costs €69/$69. A fully-featured 60-day demo is available from the 112dB website.
We'll have to wait and see (hear) how it performs, but if Redline Monitor lives up to its developer's claims, it could prove useful both for laptop musicians who like to work on the move and home studio owners who have sleeping children upstairs.