Ultra Motor has a new machine on the market known as the A2B which fits nicely into this category. Using a small electric motor integrated into the hub, the machine retains the look and feel of a normal bicycle. Constructed of aluminum, the full-suspension electric vehicle features a small lithium ion battery and is capable of traveling up to twenty miles on electricity alone. A second battery can be added, doubling the range. Of course, pedaling increases the miles between charges to as far as your legs can take you.
[Source: Ultra Motor via Hell For Leather]