If I recall correctly, because of how we group species, and because of how we used labels shared with current species to apply to species that existed in the past, humans are technically monkeys. It is like, all humans are apes, since apes came first and at no point did we ever stop being apes when homo-sapiens formed as an independent species rather then a subset of ape. The traits of an ape are still descriptive of mankind (mammal, thumbs, social culture, etc.). Going further back then the apes is where apes and modern monkeys branched paths. The creatures at that time were smaller mammals that are often described as monkey-like and had a lot of characteristics that are STILL shared in humans, monkeys and apes (forwards facing faces, detached, free hanging penises, covered in fur, all basic mammal traits, etc.). We even still retain the capacity to have a tail. The reason we are still monkeys is because at no point did we stop being monkeys. We just became specialized in a different way. The lack of tail doesn't make us less of a monkey then our fellow apes (look at the manx cat about the importance of a tail in relation to being part of a species).
I recall a video about this a while back, I'll see if I can't find it.
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here we go. seems the vid from the origional channel was delted by flagging campaign. Here is a mirror of it though.
http://www.youtube.com/watch?v=QT4Gnt1Ku4Y