Just checked the Google Blog and here's what I found:

"For the last 16 months, a lot of people have been asking us how they can sign up for Gmail, and today we're happy to be able to say, "Just go to gmail.com." From there, you can get an invitation code sent to your mobile phone, and with this code, you can create a Gmail account. Once you have Gmail, you can try out our brand new IM and voice service, Google Talk."

You will never run out of storage with this. Trust me. Unless you decide to upload your .pdf version of the Encyclopedia Brittanica, you will always have an insanely huge amount of space in which to store emails. In fact, the storage clock is ticking steadily upwards on the main Gmail signup page. You can sign up for Gmail using your mobile phone. A few nifty features:

• Photos: You can send up to 10MB of pictures to friends, family, or anyone who you think would like to see your slideshow of the mysterious Pinto Bean Mounds of Elma, Washington.
• Formats. "Basic HTML view lets you access your Gmail messages from almost any computer running almost any web browser."
• Free POP access and automatic forwarding. "Access your mail the way you want to. Download your messages. Read them offline. Use your Blackberry or Outlook or any POP-enabled device. Or forward new messages to an email account you specify. You can even switch to other email services without having to worry about losing access to your messages."

There's a lot more to it and you can read the About Gmail pages for more info.

Related: Google Talk debuted Wednesday, and here are my first thoughts about this surprisingly unimpressing service.