I. Setup Gmail Account
1. Head to mail.google.com and register for a Gmail account if you don’t already have one. If you do (keep in mind that you had to have set one up on your Android device to use the app market), simply located your Gmail email (firstname.lastname@example.org) and your password you used to log in.
II. Grab Contacts from Yahoo
1. Head over to Yahoo.com and login with your Yahoo mail account.
2. When viewing the mail, click on Contacts at the top right.
3. Choose the select all checkbox above the list of contacts to sync all of them or select individual contacts you want to sync instead.
4. Once all of the contacts you wanted to sync are selected, click on the Actions button to the right then click Export All…
5. Select Yahoo CSV for the format you want to export as and wait for it to finish exporting the csv file. Once it does, save it to your computer.
III. Import Yahoo Contacts to GMail
1. Head to mail.google.com and login with the Gmail account you plan to use/currently use on your Android device.
2. Click on Mail at the top left and select Contacts instead.
3. Click on More and then select Import…
4. Click Choose File… then select the Yahoo CSV file we downloaded earlier.
5. Select Import and wait for it to finish.
All done! Now, whenever you sync your GMail contacts on your Android device, your Yahoo contacts will be in there as well. Now, go ahead and finally delete your Yahoo mail account, who uses Yahoo mail anyway? There, doesn’t consolidating your email accounts feel good?