Welcome apathy. I too agree with the recommendation of the 510. It is a small unit. About the size of a 100 cigarette. But as others have already stated, the battery life is not great. Only one to one and a half hours at best. If you don't mind charging batteries all the time, that's no problem. You could always have several on hand. You can even buy a charger from Totally Wicked that charges five batteries at a time.
If you don't mind something slightly bigger, I would also say go with the eGo. I have one and I think it's the best. The batteries do cost twice as much as the regular 510 batteries, but they last six times longer - or more. Well worth it in my opinion. The battery itself is about twice as big around as the regular battery, but overall the unit is still small. Only slightly bigger than a regular cigarette. And it's a very classy looking unit. Not big and bulky at all, nor does it look like a detonator or flashlight. It is light weight, portable, and can be easily hidden in your hand.
As far as taste...that's a matter of preference. I wasn't a menthol smoker, so I can't help you with that one, but someone is surely going to pop up here to help you with that. You may be able to find something close.
And there you go...one popped up while I was writing this.