Image from Panoramio is by vkalathil
Image from Panoramio is by maremagna
Image from Flickr is by Himanshu Sarpotdar
Image from Wikimedia Commons is by P.K.Niyogi
Image from Panoramio is by ani2601
Nowadays these boats are used for the tourists and gives them enchanting views of the Kerala's rural life along the backwaters. Main areas where these boats now ply are the backwaters of Alleppey (aka as Venice of The East) and Cochin (Kochi).
View location of Allepey in Google Earth / Google Maps
Source of info: Wikipedia and http://www.houseboatskerala.net