WhosOn is a comprehensive system that allows you to monitor and interact with your website visitors in real time.

You'll need to make a few preparations first, of course. Visitors are tracked by embedding a snippet of code into each web page, for instance. And you'll need to set up an account at WhosOn (complete the signup form). With that done, though, you can start to benefit from the system's many features.

Live web statistics, for instance, allow you to watch visitor activity in real time. So not only do you see what'd you'd get from a regular log: how they found your site, the search keywords they used, their country of origin, and so on. But you can also see if they've been to your site before, and watch them move from page to page.

There's also support for live chat, where visitors click a link to start chatting with you (or any operators you assign to this job) as they browse your site. The chat is packed with features - custom background, logo and images, integrated spell check, file transfer, even live chat translation - yet it's also fast, works in all major browsers and doesn't require any plugins.

And a pile of other features includes full remote desktop sharing, perfect for troubleshooting customer problems; "click to call back" allowing customers to schedule a call from you; integration with Salesforce & Microsoft Dynamics CRM; PPC monitoring, automatic click fraud detection, detailed web traffic analysis, and more.

There's a Mac version which runs in Microsoft Silverlight, available after you create your account.

The system is available on free trial for 14 days, but after that is available at prices starting from £25 a month, with discounts if you pay quarterly or annually. See the price list for more.