1) Canon PowerShot SX150 IS
The PowerShot camera comes with the 14.1 megapixels 12x wide angle optical image stabilization zoom. These numeric are well above the average of other digital cameras in the price range. In addition 720p HD videos can be recorded with stereo sound. Also it comes with other features such as built-in flash, microphone and several other smart modes to help users taking photos in different lighting conditions which are all handy to have in a camera under $100.
2) Canon PowerShot A2500
Built with an attractive and slim design that is easy to carry and store. Besides 16 megapixels & 5x optical zoom there are 2.7'' screen and 28mm wide angles lens to add more value to the camera. The DIGIC 4 image processor it has, helps to take blurry free images specially the moving objects. Powered by lithium iron battery and works in ECO mode which means one battery life is enough to take more pictures. There is a dedicated movie button to use in PowerShot A2500 to capture 720p HD videos.
3) Canon PowerShot A2300
A very simple easy to use camera with a comfortable design. Features would be close towards the Canon PowerShot A2500 but differences are there. Note the specifications. 16 MP, 5x optical zooming, DIGIX 4 image processor, 2.7'' LCD, 720p HD movie recording with a dedicated movie button. The major differences between PowerShot A2300 and PowerShot A2500 would be the HDMI port which PowerShot A2300 does not have but the PowerShot A2500 does.
Youtube Video on Digital Cameras Under $ 100 http://www.youtube.com/watch?v=LZpV-yUJv8M