Well, first of all our cars use only something like 30 % of full capacity, the batteries are never discharged bellow 50-60% (not sure of exact number) and never go above 90% so our 1.5 - 2 mile range could be increased to about 5-6 miles if full, 100% charge/discharge was used. Lithium batteries have somewhere close to twice the capacity of NIMH (per weight) that would give 10-12 miles and if Toyota lowered the weight somewhere (plastic body panels etc.) and utilize the space better by using few smaller packs instead of one big, they could probably squeeze another set of batteries, again doubling the capacity to about 20-24 miles. A lot of people, especially commuters drive less than that to work and they could charge the car at work to get full range on the way home. The biggest problem in this scenario would be about 1000 full charge/discharge cycles current batteries can survive before failing (Toyota claims using 30% charge/discharge increases number of cycles to as much as 10,000 and that's why it is used in Prius and TCH). If the battery packs were less expensive, lets say $1000, instead of 3-4k, I could see myself buying new pack every two years since I would probably save more than that on gas. In other words we don't really need some kind of revolutionary discovery, we just need some really good incentive to build/buy such cars if we could push current tech to the limits and keep prices in check.