Someone mentioned earlier that a friend was a vegetarian but wore leather shoes, shame on her! I'm a vegetarian, too - I'd be a vegan if I could stay away from milk chocolate! - and thought I should mention that there are a number of stores online (and maybe a brick-and-mortar within her area) that sell canvas (cotton) and hemp products from shoes to belts to other clothing items. Payless Shoe Source sell a number of shoes that are made to look like leather but are composed of man-made materials. This can be discovered by looking on the box or on the shoe (such as under the tongue).
Although I'm a vegetarian it's due to health reasons more so than due to the understanding of the cruelty inflicted on various livestock (there are, after all, foods that promise their animals were not fed antibiotics or were allowed to roam free (free range), rather than placed in cages and/or tied down, mutilated, etc.) I still like to avoid using animal products for clothes, accessories, etc., it just seems hypocritical. Doing so, however, is difficult considering that animal products are rather common, existing in places you would never have thought of, such as a roll of film, so I try not to become too committed or fanatical (I did, however, sell a leather jacket I owned). Plus, if animals are being consumed by others, there's not much of an argument from myself in using the remains for various things as I'd prefer something be done with whatever remains there are. I still can't get myself to buy a pair of Newline Miniatures' black Fallschirmjager boots, however, after a few months of thinking about it!