What about documents other than text? In September 2003, Project Gutenberg launched Project Gutenberg Audio eBooks. As of December 2006, there are 367 computer-generated audio books and 132 human-read audio books. The number of human-read books should greatly increase over the next few years. There were 412 books in May 2008. As for computer-generated books, they won't be stored in a specific section any more, but "converted" when requested from the existing electronic files in the main collections. Voice-activated requests will be possible, as a useful tool for visually impaired readers. Launched at the same time, The Sheet Music Subproject is dedicated to digitized music sheet. It also contains a few music recordings. Some still pictures and moving pictures are also available. These new collections should take off in the future. But digitizing books remains the priority, and there is a big demand, as confirmed by the tens of thousands of books that are downloaded every day. For example, on July 31, 2005, there were 37,532 downloads for the day, 243,808 downloads for the week, and 1,154,765 downloads for the month. On May 6, 2007, there were 89,841 downloads for the day, 697,818 downloads for the week, and 2,995,436 downloads for the month. A few days later, the number of downloads for the month hit the landmark of 3 million downloads. On May 8, 2008, there were 115,138 downloads for the day, 714,323 downloads for the week, and 3,055,327 downloads for the month. This only for transfers from ibiblio.org (University of North Carolina at Chapel Hill), the main book distribution site (which also hosts the website). The Internet Archive is the backup distribution site and provides unlimited disk space for storage and processing. Project Gutenberg has 40 mirror sites in many countries and is looking for new ones. It also encourages the use of P2P for sharing its books. The "Top 100" lists the top 100 books and the top 100 authors for the previous day, the last 7 days and the last 30 days. Project Gutenberg books can also help bridge the "digital divide." They can be read on a computer or a secondhand PDA costing just a few dollars. Solar-powered PDAs offer a good solution in remote regions and developing countries. Later on, it is hoped machine translation software will be able to convert the books from one to another of 100 languages. In ten years from now, it is possible that machine translation will be judged 99% satisfactory (research is very active on that front, but there is still a lot to do), allowing for the reading of literary classics in a choice of many languages. In 2004, Project Gutenberg was in touch with a European project studying how to combine translation software and human translators, somewhat as OCR software is now combined with the work of proofreaders.