I don't know how I missed this one! From Progressive Railroading Blog
The economic stimulus package signed into law by President Obama yesterday doesn't only provide funding for transit agencies — it also will benefit those who ride the systems.
The law raises the amount of pretax income that workers enrolled in employer-sponsored commuter benefits can use to pay for mass transit from $120 to $230 per month, according to nonprofit organization TransitCenter Inc.
I don't think you can combine this with the Bicycle Benefit (which is now being supported by Commuter Checks) but this is pretty big for me - my pass is $205 per month and I definitely use another 25 in random BART/MUNI/GG transit per month, so I just got a $1320 tax deduction. And I deserve it man!