Naveen Andrews
David Cross
Jason Lee
Justin Long
Matthew Gray Gubler
Jesse McCartney
Amy Poehler
Anna Faris
Christina Applegate
Wendie Malick
Naveen Andrews as Toby
David Cross as Ian
Jason Lee as Dave
Justin Long as Alvin (voice)
Matthew Gray Gubler as Simon (voice)
Jesse McCartney as Theodore (voice)
Amy Poehler as Eleanor (voice)
Anna Faris as Jeanette (voice)
Christina Applegate as Brittany (voice)
Wendie Malick as Dr. Rubin
Anjelah N. Johnson as Julie (as Anjelah Johnson)
Kathryn Joosten as Aunt Jackie
Kevin G. Schmidt as Ryan
Chris Warren Jr. as Xander
Bridgit Mendler as Becca