You can try bringing along a light tripod or use a monopod.. Mount the camera on the monopod and it can be used as a walking stick to help you in your hike..
I used this combination on my hike in Hakkone, Japan. Loved it.. see something and the camera is already in my hand ready to snap.
Depends on how long you are hiking... 2 sets of F707 battery can last for a full day continuous usage.. but if you are hiking, I assume most of the time you are walking and not taking photos.. 1 set of battery per day is sufficient. Use the EVF and not the LCD to conserve power.
Someone is selling the F707 battery for $50 each, might be good to pack one or two more.
Otherwise, if the place is sunny enough, you can try to get a Mach1 Charger and the Solar Charger from http://ckcpower.com
I have the Solar Charger and Megaweb has the Mach1 charger, but we've never tried to combine it together to allow charging of Sony batteries using solar power before...
I've spent 22 days in the outback of Australia last Nov 01. My opinion is if u r going to do that much hiking, get a proper walking stick cum monopod. Singapore has quite limited selection. Campus Corner at Capital Building is selling the LEKI one. You may want to check it out. Or check out CP for a cheaper and lighter SLIK one.
If you choose to buy them overseas, there is more selection with brand's like LEKI, Maluku, Petzl, Black Diamond etc. They are all in the range of S$80 to S$110 each. If budget a,llow get the type with spring loading ones. Compare with the heavier and dearer Manfrotto or Gitzo ones, these walking stick work better and more convenient.
So, u can imagine my torment 22 days in the outback carrying the Gitzo G1556.
really depends where you're going and what you intend to take.
if you're hiking up waterfalls, bring a tri/monopod. a light one if possible. if you're taking night shots of the sky+stars, bring a tri-monopod - remember to let your camera out in the open for a coupla hours before taking such shots. South East Asian jungles are relatively cold and very humid at night. 2-3 days, you can't be going far.
if you're not training for some marathon 28-day trip to Nepal or something but hiking somewhere challenging, leave your tripod at home and enjoy your trip.