What do you think is the best digital camera to buy? Mostly for the outdoor and children? I bought a Canon Rebel is there anything that I can buy to attatch (specificaly) to make better close-up pictures? The EOS 1D is Canon's high-end camera line, not the Cybershot. The Cybershot is a P&S line, the asker has a DSLR.
The Digital Rebel and its XT and XTi successors are nice cameras. They aren't professional grade but they can certainly produce high quality pictures. I don't mean to be offensive but if you don't know why you'd want to move up from this camera then you probably wouldn't benefit from something like the upcoming Canon EOS 1D Mark III.
While the lens you're using is important in that lens quality matters (cheaper is generally bad and while there are some good lens under $100, I've never seen a decent quality lens under $50 and most good quality lenses run over $200), the most important thing is learning a bit about photography.
For extreme close-ups, you might want to invest in a macro lens.
If you haven't, buy a basic book and take lots of pictures at different settings. Using the same lens, take one picture at one setting, change one and take another. Compare them. See the difference between taking a picture at f/2.8 vs f/20 The best Camera ever made has to be the Sony Cybershot it great outdoors and in doors and it detects faces!! If you really mean "closeup" you are talking about a macro lens and you will be taking shots of flowers and eyeballs and ... things close up.
If you mean tight shots of faces, then you are asking about a portrait lens.
The macro lens Canon makes is a 100mm ... too long for use as a protrait lens with a Canon Rebel XT or XTi (160mm equiv to 35mm camera).
The portrait lens length best for your camera would be between 55mm and 70mm (85 to 105mm equiv to 35mm camera)
So it you also shoot a lot of landscapes, then 17-85mm might be the lens for you. I you like to shoot wildlife and sports, then the 28 to 200mm could be just what you need | 