That depends on the lens you put on the camera.
canon a560, canon a720, they have 4 x optcial zoom
digital cameras
i suggest canon sx100 which has 8mp and 10x optical zoom
i have canon sx100 which has a wonderful zoom option - 10x optical zoom
Though there are many brands that you can buy for 300 USD or less, here are some Canon cameras for that price: you can buy canon a650 for 280$ (12.1mp, 6x optical zoom) Canon sx100 250$ (8mp, 10x optical zoom) Canon a560 130$ (7.1mp, 4x optical zoom)
The Canon S-series have great zoom and can even do digital zoom for distant objects.
canon a650 has 12.1mp, 6x optical zoom, image stabillizer, etc
The Canon S90 has 10 Megapixel - 16:9 - 3.8x Optical Zoom - 4x Digital Zoom - 3" Active Matrix TFT Color LCD. The S90 offers the ability to shoot at maximum ISO 3200 at full stills resolution.
Some of the features of the Canon Powershot A95 include: 5.0 megapixels, 12x combined zoom, 3x optical zoom, 4.1x digital zoom and direct printing capabilities.
The features of the Canon A720 Powershot are: 7.1mp, 4x optical zoom and very reasonable price.
Point-and-shoot digital cameras come with a fixed lens, that often has both an optical zoom and a digital zoom. The fujifilm FinePix S3200 has a 24x optical zoom and 6.2x digital zoom. DSLR cameras such as Canon cameras with an EF mount, like the EOS and Rebel series cameras, can have different lenses attached. These lenses can have focal lengths of 600mm and beyond.
The Canon G5 is a digital camera with five megapixels, and optical zoom. It has a rechargeable battery and a zoom lens with autofocus. The Canon G5 is a high rated camera with many more special features.