The Edgeville task, Coming Like a Ghost Town, is a reference to a song by The Specials called Ghost Town. Also in RuneScape Classic Edgeville was called a ghost town.
The Varrock task, Welcome to Bartertown, is a reference to the movie Mad Max: Beyond Thunderdome.
The Al Kharid task, Open Sesame, may be a reference to the Arabian theme of the area and the famous phrase of Ali Baba.
The Canifis task, "Let Me In", is a reference to the tale of the three little pigs, who refused to open their doors for a wolf who said "Little pigs, little pigs, let me in or I'll blow your house down."
The Karamja task, "Welcome to the Jungle", is a reference to the song Welcome to the Jungle by Guns n Roses.
The Wilderness task, "Into the Wild", is a reference to the non-fiction book Into the Wild by Jon Krakauer.