Importing Contacts from Yahoo! Mail into MinuteBase
Go to your Yahoo! Mail account and select Contacts
Go to the Tools Menu and select Export...

Choose vCard Single File and click the Export Now button.

Type in code that is displayed and click the Export Now button.

Now sign into your MinuteBase account. Go to the People section and select Import People from the top-right of the tool bar.
On the Import page select vCard
Now upload your vCard file by clicking the Choose File button and selecting file you exported from Yahoo! Mail.
Click the Import button:
You will now see a list of the contacts which were successfully imported.
You can undo the process, or go to the invites page.