Robert Bernocco, an IT worker in Italy, has written a science fiction novel on his Nokia cellphone during his daily commutes! The book is 384 pages long and is called "Compagni di Viaggo".
The book is here on Lulu.com.
Despite having been created in an usual electronic fashion, it is published as a pBook. Lulu.com allows authors to publish for free, and makes money by producing pBooks on demand. The book is only printed when it is ordered. Lulu sells eBooks too, at the author's discretion.
Here is how to publish your eBook with Lulu. They take a 20% commission.
This Yahoo article tells more.