Yes, but it costs $20 per year.
Yahoo has launched Yahoo Mail Plus which includes POP access. POP (Post Office Protocol) allows the mail client, i.e. Mac Mail or Outlook, to poll the server for messages.
Apparently, Yahoo also restricts message forwarding on their basic, or free, mail service. Absent the $20 payment it looks like a message sent to Yahoo will have to be checked online at Yahoo.
Adding an Account on Mac Mail
Once you upgrade your Yahoo mail, open Mac Mail, click in the "Mail" drop down menu and select "Preferences." Click on the "Accounts" button running along the top of that dialog box.
On the bottom left you will see a + and - button. Click the the +, enter the requested info, leave "automatically set up account" checked and follow the instructions. Mac Mail is good about making account set up easy. See My Video "Mac Mail Set Up"
I got a Yahoo account for the first time to test this but given Yahoo's position on POP, I did not set it up. I imagine the process will be simple according to the above instructions, if not check back.
Alternatives
If you don't want to pay for the Yahoo Mail Plus, Google offers Gmail, a free mail service, at least for now, and setting it up with Mac is very easy and goes smoothly according to the above instructions. Google also offers IMAP (Internet Message Access Protocol) which, I like better that POP, because the mail maintains a connection to the server so no matter what I do to the account, e.g. delete, check, organize, the account look the same in all places.
MobileMe is a IMAP mail service and I reccommend that Mac users get it for a variety of reasons.
Recommended Course
Buy a domain name, i.e. yourdomain.com, and set up that domain with Google Apps Standard. Then you can have you@yourdomain.com. I think everyone should buy their own name.
Last I checked, Google Apps, allows up to 50 users on the free standard edition, at least for now, so can give out accounts to other users @yourdomain.com or make accounts for any other purposes you like.
If you want to take this route buy a domain at Go Daddy, or another domain registrar, and check back.