Luggage and bags:
I used a backpack with luggage locks and I also carried a bicycle lock to secure my bag. This especially came in handy on the Indian sleeper trains, where you sleep in a car with 50 of your closest friends. A freind of mine left his bag bext to him on the train and turned to look out the window, and someone took it (passport, money, and all). I would also reccomend locking your luggage down in your hotel rooms, just as a precaution.
I brought mosquito netting, and used it only a few times. I found that I would rather wear repellant than suffocate under the netting (it's at least 10 degrees hotter under there.)
Clothing/Shoes/Weather Gear: If you're travelling to India in the summer, bring a poncho. I would also reccomend wearing comfortable sandals - forget tennis shoes altogether. If you visit any temples, or even in many places of business, you'll be taking your shoes off over and over. And if it's monsoon season, you'll be sorry you wore socks! A few times we waded knee deep in water to get back to our guest house. Welcome to India!
Toiletries and Medical Supplies: All Women travelling to India should bring their own tampons. Although maxi pads are easy to find, tampons are relatively rare. Toilet paper is usually available, but it wouldn't hurt to carry a roll just in case.
I would also have left the Larium at home! Larium is a weekly malaria medication that has many side effects, including nausea, acid reflux, and psychological side effects like paranoia - not too helpful in a foreign country. Take mosquito repellant and you should be okay.
Photo Equipment: India is rather dusty, 3/4 of the year. Take a sturdy camera, that you won't mind getting dirty.
Camping/Beach/Outdoor Gear: Beach or no beach, summer or winter, wear your sunscreen in India! It's near the equator.
I brought a water pump, as did everyone in my group. However, only one person used his. There is usually plenty of bottled water. Just make certain that it is an unopened, sealed water bottle. I came back from India with Giardia, a water-borne bacteria, and I only drank bottled water.
Miscellaneous: If I got a chance to return to India, I would bring a box of pens to give out to children. "School pens" are a luxury item that kids often ask tourists for.
Luggage and bags:
45 liter Backpack.
Clothing/Shoes/Weather Gear: Clothing: see cultural tips. Shoes: good mountain shoes and slippers.
Toiletries and Medical Supplies: Anti-malaria pills, anti-mosquito cream, anti-mosquito net (klambu), suncream extra strong.
Photo Equipment: See: touristtraps.