You can take images using a camcorder. A word of warning: this will be time consuming to edit. But you can take still images from video recordings. If your camcorder allows it, note the recording numbers of items as you go along.
Make sure your camera is small enough to fit into your pocket. There are many small cameras available, with and without zoom facilities. You can develop the pictures and scan them into the computer, or develop them as a photo CD which can be put into your computer. Alternatively, you could use a digital camera which will linked directly to your computer.
Take shots of the same scene from different angles - you may be able to animate them later. Pictures can be resized and smartened up digitally but resizing can decrease the quality of the image, so frame your shots carefully. You can cut out parts that you don't want. Remember to make a note of what and where the pictures are - it's too easy to forget.
A tape-recorder is fine for recording people close up, but you may not want to get that close to an animal. Personal-stereo size recorders are a better bet.
It's hard to get quality recordings so finding sounds that create atmosphere are better. Sound snippets can be edited but that takes time and software. It's easier if you make short recordings. Make a note of what and where they are.
Collect only small items; they scan more easily. Coins are fabulous. Don't throw out your ticket or boarding card, security tags, tourist brochures, postcards, stamps, maps or guides.
Jot down quotes with who said them, names of places and people, dates and figures.