Looking for something like this for a long time, especially after coming to USA, I could not bring the Geetobitan, or Golpoguchchha , not even a single book of Rabindranath . The work that is being done by the West Bengal Language Academy is really praise worthy, I hope the Bangla Academy of Bangladesh will take similar actions to preserve the great works of our greatest intellectuals in the same way so it can be accessed any time from any where .
The link for the works of Rabindranath: http://rabindra-rachanabali.nltr.org/node/2
It includes his novels, poetry, songs, short stories and essays, his letters of Chhinnopotro is not included yet. As everything is in Unicode Bangla, it is easily viewable via most browsers. Very excited to see this site.
Another online archive ( I like this one more ) of Rabindranath's work : http://www.tagoreweb.in/