Organizations like The Non-Human Rights Project argue that a legal status, other than that of "property" should be granted to great apes in particular.
I could not agree more. Animals are not objects and should not be considered as such by the law, no matter which country they live in.
We do know that animals (from mice to apes) have feelings and experience empathy ** (see references below) - so how can we justify trading them as mere junk?
The question is even more pertinent when it comes to the ethical treatment of great apes in facilities using them for the greater good - (think medical research). Progress has been made and it seems that we (humans) are now moving towards a consensus that medical research should move away from animal testing where other solutions apply. However, some argue that computer simulation, in vitro testing cannot viably replace animal testing - here's an interesting article on the subject from "Speaking Of Research".
Yesterday, non human rights were debated again in the press and the battle is far from being over if some continue to think that keeping things as they are is the right thing to do. See "Sanity In the Court: Judge Denies Claims that Chimps are Persons". However, per the article, an Argentinean judge granted habeas corpus to an orangutan at the end of last year. To quote the article in Scientific American: "In Argentina, at least, Sandra now has the right to life, liberty and freedom from harm." It also mentions that in New Zealand, a river was granted rights as well "Agreement Entitles Whanganui River to Legal Identity"
This means there is hope for those who think that advanced species (and natural resources*** essential to our lives) should be granted some rights - even if they cannot plead their own case in our language.
** The Scientist "Mice Show Evidence of Empathy"
** Frans De Waal interview about The Feelings of Animals
** Frans De Waal talks about empathy
*** The idea that natural resources should have rights first was formulated in the 1970s by Professor Christopher D. Stone when the book "The Lorax" came out. You can check out this document "Should Trees Have Standing?" for more details.