Moving all-in first to act is the main weapon you have when short-stacked, but it certainly isn’t your only option. There are situations where you’ll need to take a gamble in order to chip up, either by calling or reraising all-in with a marginal hand.
For example, let’s say a very loose, aggressive player has raised before you. You know he could be raising with any two cards and you have a hand like K-9 that would fare well against his range. This might be a perfect situation to gamble. By calling all-in or moving all-in over the top, the players at your table are going to think you have a legitimate hand and you'll be able to get heads-up against the loose-aggressive player. You may not have a great edge, but in most cases you’ll have protection from multiple callers.
Another good time to gamble, although not a common situation is when there is a multi-way pot and you have a hand that plays well in such conditions. For example, a player has opened to three times the big blind in early position and has been called by two players. You have 7d-8d and only seven big blinds. A lot of players would fold in this situation, but this is a perfect time to gamble it up. Move all-in and you're guaranteed to get three, probably four callers. If your hand manages to hit, you'll have over 30 big blinds and be back in contention. It's much better to make this move against multiple players than against just one.
Does the bubble beckon?
One consideration that should factor into your decisions is whether you are in the money or not. If you’re not, and you’re not even close to the bubble, you should be more willing to gamble. If you are close to the bubble, you need to evaluate whether you can make it into the money simply by folding. I'm not a big advocate of trying to squeak into the money, but if you’ve got five big blinds and are two people from the money, you’d be a fool to not try and make it into the money, especially if the money is significant to your bankroll. The same can be said for prize jumps in a tournament. If the next person out will mean more money for you and the amount is significant, you should be less willing to gamble.