MOVING TO FRONT from Sept. 7, since an interesting discussion has developed in the comments section.
Academic journals are an amazingly cheap and secure way for publishers to make money. Cheap partly for the reason Tom [Hurka] mentions: most of the serious work (including the work that gives the journal its prestige -- writing and peer reviewing) is unpaid. And secure because university libraries are committed to keeping complete series of the main journals in a field. Yet profiteering publishers like Springer and Elsevier put up their prices regularly, and their captive market has to pay. Every year more and more of a University's library budget is eaten up by (some) publishers' unreasonable price-rises. Readers in the UK will already know that this is how the infamous Robert Maxwell made his money.
In the age of online publication, there is no reason why publishers should make so much money from our work. We don't need publishers in order to have peer-reviewed quality journals. We don't need paper publication for journals. Philosophers' Imprint has shown how you can have an excellent free e-journal which is peer-reviewed, and the Notre Dame Philosophical reviews is now one of the leading places for book reviews. Of course, these projects cost money too -- but it would be a better use of libraries' budgets to administer e-journals which are free for the whole world, than to fill the bank accounts of Springer, Elsevier and the like.
It's true that some profits of journals (e.g. Mind, Philosophy, Analysis) are ploughed back into the profession in the form of scholarships, grants etc. But this is because these journals are owned by academic societies, who have an agreement with their publishers to use a portion of the profit in this way.
It's perhaps worth noting that In the UK, the Wellcome Trust has now made it a condition of giving any research grant that the published results are deposited in an open-access online archive, in addition to being published in any peer-reviewed journal. Also, the dreaded UK Research Assessment Exercise (RAE) in 2008 will now accept any form of web-publication as publication.
These seem like steps in the right direction: to aim to make all peer-reviewed and other research available online to all, for free.
Comments are open; non-anonymous postings will be preferred. Comments may take awhile to appear (I'm finishing a tenure review, hence the paucity of postings lately).