Environmental theory and collection of ideas/Business ideas

Creating better software for file/fileset compression
File/fileset compression is much more efficient today than it was, say, ten years ago. Technology like 7zip, PAQ or the WebP image compression method beat the old technology, but they are probably still not the best. With better compression technology, it is possible to use less hardware storage for the same tasks (but note that it is also possible to use more processing power for them). It is also possible to use slow compression in order to make decompression quicker, which would probably be good for software package formats like CAB. This means that different kinds of compression methods fit for different purposes, and one of these purposes is to lessen hardware needs (and another is to keep the information more secure from hardware errors at the same time). This way, for example, one DVD would be enough for a software installer that would otherwise need two DVDs, or a Linux distribution could put its complete source code together with its executables on less CDs. If we worked hard on compression technology, it might also be possible to have fun with mathematics and win the Hutter Prize. Drawback: even if we invent a great compression technology, it is not guaranteed at all that someone will use it on optical drives, and "data easily fills the available space" on other drives, as well as the property of the rich.

Creating better audio/video/image file formats/codecs/players
Optical (CD/DVD) disks are mostly used for music, video and images. If the contents of these disks could be compressed significantly better, some CD/DVD sets would need less disks, reducing the consumption that harms the environment. If the decompression does not need too much more processing power, it is probably good to work on things like this, and maybe in the other case as well. When designing file formats for music/video, it is important to define first what information should these file formats contain (e.g. pixel images by a given FPS - frames per second - value is the easiest), and coding this information in a practical/lossless/compressed manner would be a nice mathematical task. Drawback: musicians tend to release only a few songs at a time fit on one CD, and most of the movies fit on one DVD, and even if they do not, Blu-Ray disks have appeared on the market. (However, similar technology could help saving the quality of the data written on CD/DVD, by properly placed redundancy, and more independence between parts of data. Actually, this might interest people more than compression.)

Creating a proper website for local barter
(Internet-only idea...) There are already websites which allow successful local barter, but in fact, these websites were not designed for this purpose. On websites for local classifieds it is not local barter which dominates, and the people willing to swap rarely have things which are mutually interesting, and on a book-swapping website it is impossible to limit the receivers to only local people, and thus the swapping is probably not economical due to the postage fees. However, if we joined the advantages of both kind of websites, then it would be worth capitalizing on this opportunity for much more people. In order to increase the range of exchange, it would be worth using virtual credits on the website, and the users could decide how much virtual credits do they ask for their stuff. These virtual credits could be spent on the purchase of the things on the site, but the website would deduct some percent from it for the costs of maintenance and other causes, from which the owners of the website could equally buy some used things on the site, or even sell them in a shop. This way this local exchange website would work in a similar way as the now-popular local money, with the difference that virtual credits should not be converted to/from real money for marketing reasons. For reusing stuff, the exchange of used things can have a relatively high environmentalist value. Drawback: the implementation of this might need significant financial resources.

Increasing communication for efficiency
(Internet-only idea...) Computers and the Internet help making the communication among people more effective, and this communication may make the protection of the environment more effective. For example, communication may help people decide what events should happen, and these different events should happen where the demand is the greatest for them. This way more people can disengage with the same use of energy, which also means that less energy is needed for the disengagement of the same number of people. This could be implemented by a software for voting, and this software would be available both from mobile devices and on the Internet. For example, people could vote about what movies they would like to watch in a cinema for old movies, what performances they would like to watch in a theatre, where should the next concerts of a band take place, what books should have movie versions, etc. There are also cases when it is good for the people if other people do not choose the same opportunities as themselves, for example, if they want to spend their holidays on a place where there won't be a great multitude of people, or if they would like to work at a place, and do a job for which there is not much competition. The duty of the software would be to utilize the power of communication at the decision making in more and more similar cases. Drawback: the implementation of this might need significant financial resources.