Bring with you:
*Good chocolate. So hard to find here! (and expensive)
*Ziplock bags, the good ones which will last
*Bandaids for all those rubbed off blisters from all those new pairs of shoes
*Painkillers. The last thing you want when you have a headache is to deal with a chemist. Just bring one of those tiny bottles. Buy more when you need it.
*Girls: Safety pins to hold all those clothes on! They're available here, but I haven't found them yet...
*Ditto on the lipgloss mentioned above. I've seen makeup, but not lipgloss or chapstick.
*Journal and a couple of your favorite pens
*Individually wrapped baby wipes.
*A Western towel. We found some, actually, this weekend, but you'll want it pretty soon after arriving and they're not very easy to find.
*Underwear (and girls: bras).
*Good coffee, if you drink it. A lot of ground coffee here has 30% chicory. Without is available, but it may take a bit of work to find.
*Some of the foot care stuff people have talked about on other forums.
*Rechargeable batteries and a 220 V. charger. I've had a hard time finding any that aren't VERY expensive--what I've found cost 450-600 rupees for two, the same as I'd pay in the US for 8!
*A deodorant stone/deodorant crystal. In the US, they're at the natural food and hippie stores. They work marvellously and you don't smell at all! They don't have a smell, either, so you don't add to all the other smells surrounding you all the time. They don't work as an anti-perspirant, though, just anti-odor. But, with all the walking it's easy to sweat a lot here, and with all the new foods and combinations of air and environment, you're more likely to want something stronger.
*A light jacket. It does get cool at night right now, especially on a cycle or in an open auto.
(I'm not traveling much yet, so that'll have to come later).
If you're staying long term, bring:
*A French press (if you like coffee)
*An oven thermometer and kitchen timer.
*Sometimes baking pans are hard to find and expensive. Bring a couple if you have weight. Cookie sheets, especially, need to be very small, though, as the ovens are very small when they're available. Casserole dishes are available, but at American Pyrex prices, so pretty spendy.
*jeans. At least one pair. You'll want them for days when you feel like being a Westerner.
*Pictures of your family and where you're from--and maybe a small map of the US or Europe so you can show where you're from.
*Taco seasoning, etc. They have lots of spices here, but when you're homesick, it'll be annoying to have to figure out the right balance. Pumpkin pie spice, things like that--your favorite stuff.
Buy as soon as you get here (very easy to find):
*A small flashlight/torch that will fit in your purse.
*A small umbrella (it's nice for the too sunny days, too. No one here wears sunglasses, and it seems like a good idea not to sometimes. A lot of communication comes through eye contact and people being able to see your face, especially when crossing the street.)
*A large bag for shopping--like those horrible purses old women carry. It's a lot easier to carry when it has a strap to go over your shoulder, especially when you're on a motorcyle. And a zipper is good for security. I got a small messenger bag, which is also easier to protect than a backpack.
*Kleenexes (aka face tissues. aka toilet paper for your face according to our grocer.
)
*Small Visa/passport type photographs. We got 10 for 80 rupees. Very helpful for visas, and they wanted one for the phone paperwork as well. If nothing else, give them out to your friends when you leave. haha.
*A small padlock for your suitcase or a bag that you keep valuables in.
If you're staying long term:
*a plug in water boiler (it's like a pitcher, you put water in, press a button, it boils it. Goes great with your French press.)
*A map of the city. We got an Eicher map of Bangalore for 200 rupees and it's amazing. It has every street as well as apartment complexes, banks, tourist sites, etc. marked. The auto drivers can't read it, but it helps for counting how many streets to pass before your turn.
Don't bring:
*Shoes, at least not more than one pair. Bata has really good walking shoes really cheap, and they're EVERYWHERE, in Bangalore at least.
*Your cell phone from the US. Unless you have tri-band frequences, even if you unlock it, you can't use it here. I bought one for 2300 rupees (a friend told me I probably paid about 100 too much. I bought on MG Road and it was easy, so 100 rupees worth of convenience) and the SIM card was 800 rupees. They only wanted a copy of my passport and driver's license. For a monthly plan, they'll want a lease agreement.
*Clothes. Only bring enough for a day or two. We bought ready made the first day I was here. It was 2000 rupees for 3 tops, 2 dupatta, and 2 pairs of pants. It's more expensive ready made, but they were very well made and now I have some nice things for when I need them. Stitched, clothes cost about 425-500 per outfit including fabric and stitching. Chiffon is less, embroidery is more.
*A watch. Why bother? (*grin* I actually just use my cell phone.)
*Appliances. It's way too much trouble to deal with converters, etc.
*Shampoo, conditioner, deodorant and contact juice are readily available at the mall. Just bring enough to last for a bit until you find more.
Will add more as the mood strikes! *grin*
3
)
(You can buy good ground coffee without chicory, too, but for avid coffee drinkers, that three days before you find the best stuff and try all the new kinds will be torturous! Sheesh. Amateurs. 
