A handful of Nissan electric taxis are now cruising the streets of Mexico City. I haven't actually seen any yet but am eager to ride one once I do. This Al Jazeera report says the meter rate on the taxis begins at about the equivalent of $2 US, so they are equivalent to more expensive taxi stands rather than those that cruise the streets looking for passengers. In any case, if it helps the air quality in my book it is worth the money.
I've never ridden an all-electric vehicle, only a hybrid. I'll report back on the experience.