Recently California passed a rule that extended access to the state's carpool lanes for zero and ultra low emission vehicles until 2015. Part of that regulation update included the phase-out of access for hybrids like the Toyota Prius and Honda Insight. Despite hybrids being relegated back to the crowded lanes, Honda still has two vehicles that do qualify, the FCX Clarity and Civic GX.
Unfortunately, at this point, the number of fuel cell powered-Claritys in private hands remains in the single digits. Even the natural gas-fueled Civic GX is comparatively scarce. Perhaps now that the Civic will have HOV-lane access until 2015, more buyers will migrate away from hybrids. One advantage of the Civic is getting a Phill fueling rig that hooks to your home natural gas supply so that you can fill the Civic in your garage.