Review (5/5): You'll never use a manual toothbrush again.
My dentist recommended the Oral B Vitality and I purchased one in June '08 and have been using it ever since. To be honest I purchased this particular one because it was green (they have a blue version also). This is an inexpensive electic toothbrush that does the job. According to the directions, if it is charged it the first time for ~16 hours it stays charged for 5 days of uses for 2/day at 2 minutes/use (the brush has a built in timer and pulses at 2 min.). I charge mine every few days by leaving it in the charger overnight, but you can leave it in the charger constantly as long as you let the battery run down once every 6 months (extends rechargeable battery life).
The dual clean comes with the larger, "dual clean" brush heads, but the brush is compatible with most of the Oral B brush heads (including the smaller single brush head ones). I used both the dual and the singles and both worked fine, but switching from one to the other takes a couple of days to get used to as you get used to the size difference.
My then 1 year old Lab seemed very interested in the toothbrush while I was brushing... so I swapped out the brush head (the brush head is the only part one's mouth touches) and tried it on his teeth and he was very agreeable to it... so now that he has his own and I brush his 1-2X/wk I'm hoping it will delay a costly dental visit for him. I have heard they can be several hundred $$.
I bought one for my sister this past Christmas (along with extra replacement brush heads) as she was shopping for one and she likes it also... makes a good gift.
I was back at the dentist in Dec. '08 for a check-up and while my teeth are usually pretty clean anyway they were even cleaner... he practically had nothing to do... so I think that speaks for itself.