Google has recently released a browser plugin for Google Earth which lets you browse 3D maps and locations from within your browser. This plugin works standalone means it does not require you to have Google Earth already installed on your PC.
Google Earth Browser Plugin can be downloaded using the link provided at the end of this post. This plugin currently supports only Firefox, IE6 and IE7 and is consumes a lot of memory while running so make sure you have enough RAM before downloading and installing this plugin.
Courtesy: Google OS