Everyone's in Nepal - Magnificent Mountains View, exciting wildlife safari, thousands of year's temples, ethnic peoples and unforgetable festivals all make winning subjects. But beware of experiencing your trip through a lens. The camera can provide great memories, but don't hesitate to put it away when it's getting in the way of the real thing.

Equipment of Photography
The first rule of packing photo gear is to keep it to what you can realistically carry. For many travellers, this will mean sticking to a pocket-sized point-and-shoot model with a built-in flash. These cameras are unobtrusive, lightweight and easy to use, and the digital ones make it particularly easy to send pictures home by Internet. The drawback is a lack of versatility, since the lens only zooms so much, and you can't usually override the automatic functions.
Bringing an SLR (single lens reflex) camera involves a tradeoff between higher performance versus extra bulk and security precautions. To get the most out of your SLR you'll want a decent selection of accessories. Zoom lenses lighten your load, minimize lens changes and give you a whole range of focal distances to choose from. Two or three should do it: something in the 35-80mm range, an 80-200mm, and a wide angle (24mm or even 20mm). On longer lenses, the lower the f-stop available, the more flexibility you'll have but the greater the bulk (and price). It's also good to have polarizing or split-density filters to cut down on glare, plus UV filters to protect lenses. A flash is useful for filling in shadows, and a tripod for long exposures. And if you're carrying all that booty, you'll want to make sure it's protected in some sort of bag - either over the shoulder, strapped to the chest or around the waist - which you shouldn't let out of your sight.

In some situations a cheap disposable camera (sold in tourist areas) may be your best bet. On a raft trip, for example, you can take pictures with a disposable without worrying about ruining it in the water, whereas a regular camera will have to be kept stowed away in a storage box most of the time while on the river.
If you're thinking of buying a camera for your trip to Nepal, you might consider waiting until you get there, since equipment is quite reasonably priced in Kathmandu. Shops there also sell most camera accessories - batteries, lens filters, tripods - but it's probably best to bring these with you just in case they don't have the exact thing you need. Remember that batteries go flat more quickly in cold temperatures.

Most major brands of film (prints and slides) are easily obtainable in Nepal's tourist areas, and prices are about the same as or even cheaper than back home. Off the beaten track, though, the selection is pretty thin. Have a selection of both fast (ASA/ISO 200-400) and slow (100, 64 or even 25) film on hand to deal with different conditions.
If you're bringing film into the country, pack it in a lead bag (available in camera shops) or carry it as hand baggage and have it hand-checked - new airport X-ray machines are coming into service worldwide that are programmed to turn up the power if they spot suspicious-looking items, and this can fog film (high-speed film is more vulnerable).
Labs in the main cities and towns process most types of film; they usually do an okay job with prints, but can't be trusted with slides. Have important photos processed outside Nepal if possible.

All the comments about bulk and security for still cameras apply even more so to video cameras. Note that you have to pay a steep extra fee to bring a video camera into certain parks and signts. Nepal's electricity is 220V/50 cycles, which means North Americans won't be able to recharge battery packs without an adapter (available locally).