In the same way it rocked the Internet-search world, Google has caused a stir in the Web-mail arena, this time with its recent introduction of Gmail Beta. At the time of Google's announcement of its new online mail service, leading services such as Yahoo Mail and MSN Hotmail were offering free e-mail accounts with one or two megabytes of storage, while Gmail boasted a whopping one gigabyte of storage for free.
Not surprisingly, the competition took notice. Yahoo was the first to take action, upping the storage maximum for its free service to 100MB. Microsoft has said it will dole out roomy 250MB in-boxes for its free Hotmail service later this summer, but for now, you're still stuck with the minuscule 2MB max. Lycos and Netscape have yet to respond to the Gmail threat, keeping mum about their 5MB in-boxes.
Right now, the only way to get a Gmail beta account is to be invited. Gmail account users are provided with a certain amount of invites every so often. So far (during my first month as a user) I've recieved 6 invites that I can give out. While the method google uses to send invites to its users is not really known for sure, it is estimated that each account receives 6 invites per month. To quote from the Gmail help section:
As we make way for more accounts, we may periodically allow you to invite others to join Gmail. When we do so, you will see an invitation link in your inbox. If you do not see the invitation link, that means that we are unable to provide you with additional invitations at this time.
Source: Cnet