All barbets play the important ecological role as seed dispersers in forests.

Asian Barbets
The family Megalaimidae has 26 species living in wooded areas from Tibet to Indonesia. You are already familiar with some of the Megalaimidae family barbets found in India like the coppersmith barbet,lineated barbet etc.

Coppersmith barbet Photo1 Courtesy of Akshay Charegaonkar, Photo2 Courtesy of Ron Knight
Lineated barbet Photo1 Courtesy of Vijay Anand Ismavel, Photo2 Courtesy of J.M. Garg

Now let us venture out to the wider world of exotic barbets!!!

African Barbets
The Lybiidae is a bird family containing the African barbets.There are 42 species.They are found throughout sub-Saharan Africa, with the exception of the far south-west of South Africa. Here are some of the interesting species of African barbets just to kindle your curiosity.

Yellow-fronted Tinkerbird
Photo Courtesy of  Derek Keats

White-headed Barbet
Photo Courtesy of  Peter Steward
        

Double-toothed Barbet
Photo Courtesy of  Peter Steward

American Barbets
American barbets, family Capitonidae, are birds which inhabit humid forests in Central and South America. They are closely related to the toucans.The diet of barbets is  dominated by fruit. They also take insects and other small prey.

Red-headed Barbet
Photo Courtesy of  Rafy Rodriguez

Toucan Barbets
The toucan-barbets, family Semnornithidae contains only two species.The Semnornis toucan-barbets are found in the Neotropics.They are social, and may be seen in small groups of up to five or six individuals, or as singles.The diet of these two species are made up of fruits and insects.

Toucan Barbet
Photo Courtesy of  Jerry Oldenettel

References
Barbet page @ wikipedia and its links