Caillat and Dennen, who both accompanied Mayer on his "Mayercraft" cruise-ship tour last fall, will add support on all dates for the trek, which is being presented once again by Blackberry, who also sponsored Mayer's 2007 summer run.

Mayer continues to support his Grammy-winning album, "Continuum," which surfaced last year and spawned the hit "Waiting on the World to Change." The disc, which follows 2003's "Heavier Things," is Mayer's third full-length effort and marks his first time as producer.

Mayer also released a six-song EP, "The Village Sessions," in December, featuring the members of his John Mayer Trio (drummer Steve Jordan and bassist Pino Palladino), as well as Robbie McIntosh of The Pretenders and Ben Harper. The EP features acoustic and alternate versions of songs from "Continuum."

Billboard.com is reporting that a new CD/DVD & Blu-Ray package from Mayer will hit stores this summer, featuring a live performance recorded at Los Angeles' Nokia Theatre last December.