I've been testing the E-Zip 2008 Trailz bike by Currie Technologies. This electric bike is quite inexpensive -- other electric bikes range in price from $700 up to $3000 in the U.S. For half the price, this is a solid bike with good range and power. My bike arrived partly-assembled in a box. It took me about an hour to attach the seat, front wheel and pedals. The lead-acid battery took about 2 to 3 hours to come to full charge. The weight of this battery and the motor make the E-Zip a heavy bike.
Using the electric motor on this bike is simple -- once you've started pedaling, you can turn the throttle, and the motor kicks in, giving you an immediate boost. On hills this really makes a difference -- you can speed up most hills with ease.
I've found that the range of a fully-charged battery is about 10 miles -- that's if you make liberal use of the electric assist. If you just use it to go up hills, the charge will last for 20-25 miles. The battery detaches so that you can charge at a cafe or an office. You can also add a second battery for $120 from Currie Technologies, that will double your range (but also increase the bike's weight). Unfortunately, the bike's manual says that the lead-acid batteries are only good for one year.
If you use this bike for a commute that is 20 miles or less, you could definitely arrive at the office without breaking a sweat. I was pleased by the power of the motor. It was easy to achieve speeds of 25 mph while pedaling lightly.
So while bike is heavy and lithium-ion batteries would be nice, it's certainly an inexpensive way to enter the world of electric biking.
The E-Zip Trailz is available from Walmart.Com for $348 (select "Electric Bikes"). It's only available online - but shipping is free if you pick it up from a local store.