For thoses who needs a perfect cloudless texture of the earth, and in every seasons, here is a link to the last build of the nasa "blue marble" project, from August 2005.
Like this :
With topography!
go to the
San Diego State University Web Site You can get there big images of the earth (what is big, hum 2.2G picture - 21600 * 21600 in png IS big)