Palm's official web store in the U.S.has posted a simple note saying this device is "no longer available".
The Treo 650 has been Palm's most popular smartphone since it was introduced in 2004, and in the subsequent years has been offered by carriers all around the world.
This product, though, is starting to show its age, and over the course of this year Palm has come out with a number of newer models.
In January, this company's first Windows Mobile-based smartphone debuted, the Treo 700w. This was followed later in the year with the Treo 750v, another device running that same operating system.
This spring, Palm came out with a new Palm OS-based model, the Treo 700p. And, of course, another Palm OS model, the Treo 680, debuted just a week or so ago.