iZoom is a plugin onhover image magnifier for jQuery. Just download the plugin and initialize it like:
jQuery('selector').iZoom();

<img id="selector" src="link-to-your-photo" />

The plugin has several optional settings. Take a look here:
jQuery('selector').iZoom({
    diameter: '200px', //set the loupe diameter
    borderColor: '#bbb', // set the loupe border color
    borderStyle: 'inset', // set the loupe border style
    borderWidth: '1px' // set the loupe border width
});

By default, the loupe has diameter 150 pixels, border color #ccc and border style inset. I put here a few demos:
jQuery('#myPic1').iZoom({
    diameter: '200px'
});

<img id="myPic1" src="00507_macroant_1680x1050.jpg" />


jQuery('#myPic2').iZoom({
    borderColor: 'green',
    borderWidth: '3px'

});

<img id="myPic2" src="00507_macroant_1680x1050.jpg" />


jQuery('#myPic3').iZoom({
    borderColor: '#f00',
    borderWidth: '3px',
    borderStyle: 'double'

});

<img id="myPic3" src="00507_macroant_1680x1050.jpg" />


The plugin is compatible with IE 6+, Firefox, Safari, Opera, Chrome and probably other browsers.
Grab the latest version. Choose your compression level: If you find some bugs or you have some ideas please send me a feedback using the form on the my site.

Version 1.3:

Version 1.2: