I'd echo what HOPS has said. A good E-cig with an automatic battery shaped like a real cig was the way I went, after getting one of the huge battery types.
The V2 E-cig vastly exceeded the other E-cigarettes I've owned and tried, and it came with both manual and automatic, the only time the manual gets used is when the other one is out of charge.
The V2 E-cig automatic battery also starts to "kick-in" straight away, I don't have to take a "primer" pull.
If you do go for the V2, avoid the starter kit. As this comes with 2x batteries (manual and auto), a charger and 10 pre-filled cartomizers. I'd go for 1 x auto battery, a charger and 5 refillable cartomizers bought seperately, which is a lot cheaper and you can tailor it to your needs. You can buy the juice from somewhere else, the V2 juice is ok so you could get a bottle from them, but it's a lot better from the bottle than the pre-filled carts and lasts a lot longer.