Google's GMail attachment size has been doubled, from 10 MB to 20 MB, meaning you can now send bigger files in one email.
The service may not be live yet, and it has been pointed out that most of the other email services won't support your receiving 20 MB worth of attachments, unless the person you're sending an email to has a premium email account such as Yahoo Mail Plus. I guess you'll just have to stick with emailing 20 MB worth of attachments to other GMail users, for the time being. Google is often the first mover to increase size restrictions for its free email service. Yahoo recently increased its free email storage capacity to support an unlimited amount.
For those that would prefer to use a third party for the sending, storing and receiving of large files, there's always services like YouSendIt and Tubes, among others.