Christina Aguilera looks pretty happy hawking her music the front page of the new ReDigi web site. But her label and manager Irving Azoff probably won't be happy to learn that under the headline "Axing your Aguilera?" ReDigi is really selling "used" downloads of Aguilera's songs for as little as 59 cents.

Using catchphrases like "All About Arcade?" (Fire) and "Craving For Carlos?" (Santana) , ReDigi, a site that many observers are convinced is illegal, went live late yesterday,

ReDigi’s is not some shady outfit based in the Soviet Union, but rather a group of Cambridge, MA based technologists whose claim of legality is based a proprietary ReDigi Music Manager client (video demo below), which they say enables a music file to transfer from one user to another without allowing multiple copies to exist at the same time.

“ReDigi’s technology signifies an important transition in the digital space, beyond the scope of what anyone thought was possible,” CEO John Ossenmacher said in a statement. “By allowing consumers to sell their used digital music, we are giving digital goods a resale value for the first time ever and opening a new realm of what is possible in the digital age.”

No so entertainment attorney Rob Falk told Hypebot when looking at the service back in April. "A legal music download is generally issued as personal license to use, and I believe that by its terms, is non-transferable."

Watch the video demo.  What do you think?