Simple and powerful Google Analytics tool recently introduced a new feature which allows to see all visitors on your site in real-time.
To use the feature you simply need to enable Google Analytics tracking for your store as described in How do I configure Google Analytics in Magento article, login into your Google Analytics account and navigate to Home > Real-time > Overview tab to see all visitors online:
Real-Time will track the immediate impact to site traffic during online marketing campaigns or social promotion.
For more details about the feature please refer to Google Analytics blog:
http://analytics.blogspot.com/2011/09/whats-happening-on-your-site-right-now.html
