eBay Phone Alerts' navigation chart
(pic via Mashable)

Noting a deficit of a-la-cart ad-serving in telecommunications, UnWired Nation makes web content accessible through audio recordings.

Mashable sheds more light on the technology by using the example of a blog on which users can dial a number to hear a particular post read out loud.

eBay Phone Alerts, a service that allows eBay members to get bid alerts as an auction draws to a close, is now serving such ads with services rendered by MobileAd Technology, a platform created by Apptera.

A press release claims that the ads can also be targeted:

"When UnWired Nation calls an eBay user notifying them of their bid status for a camera, the user could hear a short ad– served by Apptera's MobileAd Technology — about camera accessories, prior to the user's opportunity to bid on the auction."

MobileAd Technology also serves ads on AT&T's 800-YellowPages services.