Two years plus 200 million downloads of Skype's voice client equals 60 million registered users. Like Pre-Google search engines, PC-to-PC phone calling had been around for years, but was headed nowhere in particular before Skype. Today, new features make Skype ready to handle your business calls--and much more.

THE MATH IS mind-boggling: Two years plus 200 million downloads of Skype's voice client equals 60 million registered users. Like Pre-Google search engines, PC-to-PC phone calling had been around for years, but was headed nowhere in particular before Skype. Today, new features make Skype ready to handle your business calls--and much more.

Version 1.4 of Skype's tiny voice applet achieves better-than-landline call quality and adds free call forwarding--a critical feature for business callers, who make up a quarter of all Skype users. You don't have to be logged in to a computer anymore, either: Just have your incoming Skype calls ring on any three landlines or mobile phones simultaneously.

Of course, off-internet calls aren't free; you'll need a SkypeOut account. This calling card-like service lets you call anyone in North America, Australia or Europe for about 2 cents a minute, and most other countries for less than a quarter a minute.

The new Skype Groups lets you equip an entire office with phone service and manage all your workstations and call logs over the web using a single business account. For anyone uncomfortable with a $ 10 headset, new Skype phones like the $ 100 Linksys CIT200 can deliver that old-fashioned telephone experience.

Skype also has new ways you can provide toll-free access to distant employees, customers and partners. For $ 35 a year, SkypeIn will give you a local phone number with free voice mail in any area code in the world. Add Skype's free links to your web pages or Outlook e-mail, and your Skype-equipped customers could be calling your sales or support lines with a mouse click. Up to four conferees can participate in voice or IM exchanges, transfer files or engage in extended chats. By the time you read this, Skype will have also added video-conferencing.

Skype is working with other developers to add these features to search engines and other software, and its merger with eBay could eventually bring another 225 million eBay and PayPal customers into its user base.

By Mike Hogan