Via Lifehacker comes this great hack on how to get Yahoo! Mail Beta without an invite.
Admittedly, it's unofficial as of now, but having tested it, I can confirm that this works!
The steps are as follows:
- Log in to Yahoo Mail
- Click Options
- select Account information from the left panel
- go to Member Information, click on Edit
- In General Preferences, Preferred Content, you'll see your region in blue hyperlink (e.g. Yahoo! U.S.)
- Click on your region
- Change the setting to either Yahoo UK, France or Germany
- click Finished
- You might see a TOS page.
- Click on "I Accept"
- Click on "Finished"
- Go to Yahoo mail
- you'll see a page that says "It's the New Yahoo! Mail Beta… and you're invited."
- click on "Try Beta Now".
- Log off
- Log on again
- Accept the TOS again
And voila! you are on!!