But there are still plenty of free Web tools available that are particularly useful for mobile professionals. Here are a few I use.

Gmail: Web Mail, Online and Off

Over the past few months, I've transitioned from Microsoft Outlook for e-mail to , Google's free online e-mail service. Gmail has lots of benefits for people on the go, such as the ability to use and search your messages from any Internet-connected computer or phone. You can also use instant messaging, send and receive SMS text messages, and carry on video chat sessions, all within the same interface.

Frequently, Google engineers add new features to Gmail. Among the latest is , which downloads a large cache of Gmail messages onto your computer. This makes your Gmail e-mail messages available when you don't have an Internet connection, such as when you're on a plane. You can compose or reply to a message offline; Gmail will send it when you reconnect. (Google last year.) I've tried Gmail Offline and it works as advertised.

Skype: Voice and Video Chat for Two