In typical boom fashion, uber-hyped Tellme raised $125 million (at least), based on an unproven assumption. This one, that people wanted to call up and listen to the web on their telephone. (From the News.com article: "Tellme is one of the most prominent of a host of companies that have sprung up over the last year purporting to offer Internet-style information and services over an ordinary telephone. Long-term consumer demand has been difficult to gauge...")
I don't know whether this assumption was faulty or not. Although it never occurred to me to use the service (except for the DIY part, where there were some interesting possibilities), perhaps the faulty assumption was just that they could make money at it.
Anyway, they ocurr to me now and then and no one ever hears of them, so I checked, and, as expected, they're still around but doing something completely different now: "Tellme helps leading enterprises and service providers...maximize the value of every customer call." Well blow me down.