This is an addition to Avi's answer.
The varieties are sweet and bitter almond (the latter is the one with amygdalin which is the source of the cyanide as well as the aroma (benzaldehyde)) almonds, see http://en.wikipedia.org/wiki/Almond#Sweet_and_bitter_almonds.
Here (Germany) bitter almonds are sold only in small amounts for baking which are labelled that they are not for raw consumption, and are to be kept away from children. Here's a newspaper article from 1964 about a discussion whether the allowed package size should be reduced to 50 g (which is AFAIK the currently available package size). The article argues that till then the opinion was the awful taste provides enough safety. For the counter argument they cite a number of studies that conclude many people are really bad at smelling and tasting, and that the knowledge about the bitter almonds in the population was decreasing.
However, smelling of cyanides has been studied a lot in the 1950s and 60s, and huge differences in the human "limit of detection" and substantial numbers of people who do not smell cyanide have been found (Literature list 1 Literature list 2). Also how people describe the smell of cyanides differs a lot (not surprisingly, as at least in western cultures, smells are hardly described at all, so talking about smells is difficult, and also considering the huge differences in smelling sense between people).
Personally, I smell cyanide, and I perceive the smell of the cyanide as very different from the smell of the benzaldehyde (almond aroma, amaretto, ...) which are both released by hydrolysis of the amygdalin. I never tried tasting bitter almonds (only smelling, e.g. mashing them with water, and if you like to separate the cyanide smell from the benzaldehyde smell, with a small amount of an odorless acid)
Even if you happen not to be able to smell cyanide, the benzaldehyde content is very remarkable compared to sweet almonds. So if the almonds you ate tasted and smelled like "normal" almonds, you ate sweet almonds.
