I am on a job hunt and the website glassdoor is of great help. Like we use mouthshut to read reviews about various products, people can use glassdoor to read reviews about organisations, interview experience or salary trends.
The reviews are anonymous and it hardly takes any effort to give an honest review about your present or past employee organisation.
The only problem is that even after u sign in u have to write anonymous reviews about a company or organisation to further utilise the service of the website. Well since I am a fresher I have only interview experience. That said the website is very useful!