Shortstack in a cash game, although not my strategy of choice, can be a somewhat viable strategy if played 'correctly'. Most that I've seen in the micro limits who buy in for the minimum play extremely tight preflop, but since the ratio of stack size to blinds is so small, the small-stackers get pot committed much more easily, and therefore, as dweezel pointed out go all in after the flop regardless of flop texture, doing this both in the hopes of picking up blinds and also because theyre so pot-committed. (<---this is why I don't like this strategy) They wont often enter pots that they don't open themselves. Harrington talks about shortstack strategy in 'Harrington on Cash Games Vol 1' as well as other stack sizes in relation to blinds, and the relevant strategies that go along with them. Some of the more experienced higher-limit grinders can answer this better than me for sure.
There are of course exceptions, the people who only buy-in for the min because they want to play extremely loose with the minimum at risk. Theses guys are usually easily spotted, rarely making a standard raise PF and instead just shipping it all at once. Both styles of player often leave after a double-up as dweezel also said.