via AP and Wired.com:

GENEVA -- The use of robots around the home to mow lawns, vacuum floors and manage other chores will increase sevenfold by 2007 as more consumers snap up smart machines, the United Nations said.

Most of them — 570,000 — were robot lawnmowers. Sales of vacuum cleaning robots reached 37,000.

http://www.wired.com/news/technology/0,1282,65408,00.html?tw=wn_tophead_7