You've gotten through the first part of this discussion and for your trouble, you'll now be treated to even more.  Swell.

1. Digital Cameras.  The advantage is that you can see what you photographed instantly.  And if you didn't get the shot, you can try again.  And again.  And again.  And now the tour guide is telling you to get a move on.  Digital does not absolve you from taking pictures correctly the first time, and the key discipline is not to get too hung up. 

For your camera, buy the most megapixels you can.  For landscapes, you need to get the biggest sensor (physical size) possible.

AC power is the single biggest problem on  the road.  The first step is to make sure that the charger/AC adapter that comes with your camera can handle 220V electricity.  That way, all you need is the $5 plug adapter (which you can get anywhere) to convert to the local wall socket.  That way, there is no bulky 110/220V converter to contend with.

For your rechargeable batteries, if your battey lasts 4-6 hours, take 3 of them.  Most digitals do not take standard off-the-shelf alkalines in a pinch, so don't get caught with your pants down.

2. Batteries. If you anticipate burning a lot of AA batteries, consider rechargeables.  Everready makes a 4-bay, 30 minute NiMH charger that runs on 110/220V.  Note that these get very, very hot when they are in operation.  While we are on the subject of batteries, these are the primary differences between batteries:

Carbon-Manganese (1.5V): do they still make these anymore?  Low capacity; contain toxic acid.  Avoid.

Alkaline (1.5V, 1500 MaH, $0.40/per).  High capacity, long shelf life.  Low in toxic content.  "Acid" washes out of battery chambers with ordinary vinegar.  The two leading brands are the Everready Energizer and the Duracell.

Nickel Cadmium (NiCD) rechargeables (1.2V, 1200 MaH, $1.00/per).  High capacity, medium shelf life charged (10% per month self-discharge), long service life (1000 cycles).  These are designed for high-drain applications and deep discharges.  In other words, they are the Mustang that you need to drive so it doesn't go to seed.

Nickel Metal Hydride (NiMH) rechargeables (1.2V, 1750-2300 MaH, $2.50/per).  Higher capacity, short to medium shelf life charged, moderate service life (300-500 cycles).  These are designed for shallow discharge.  Fully depleting these degrades life.  Energizer and Sanyo (the same batteries) are the best.

Lithium (Energizer L91) disposables (1.8V, 2900 MaH, $2.50 per).  This is the killer app of disposable batteries, with twice the capacity of normal alkalines, a 15 year shelf life, and 33% less weight than an ordinary alkalines.