Anyways, in my opinion, one of the primary purposes of art is to provoke thought and to allow us to view the world in a new and different perspective. Fashion on the other hand is influenced by more pragmatic considerations--it is clothing after all, that needs to cover our body. But more than that, I believe that the primary goal of fashion is to achieve a pleasing aesthetic effect, or put simply: to look good.
Needless to say, like any other field of design (e.g. architecture, interior design, etc.) the fashion world certainly has an artistic component to it, but it is not in of itself, art.
There is a spectrum of course where some clothing is so devoid of practical and aesthetic value it is clearly meant to be art. A lot of designers intend their runway shows to be an artistic experience and come up with some pretty whack stuff. I don't think it can taken as anything other than art.
I would put Lady Gaga's outfits in the same category. That's one of the reasons why I resent Vanity Fair placing her on its Best Dressed list. I don't think her clothing is fashion so much as it is (bad) art.
I recently came across a Chinese artist named Liu Bolin who photographs himself upon having painted his clothing in a chameleon like-manner so that he completely blends in to his surroundings. Some of the photos are amazing. It looks like there is a ghost in the image. See if you can find Waldo in these images:
And my personal favorite:
Pretty amazing stuff, huh?
I'm not quite sure what this has to do with fashion--it clearly belongs more to the realm of art. However, I wouldn't be surprised if some fashion designer is influenced by this art form and incorporates some of these elements into his or her next collection.