Whether I am playing at an API event, or at a casino I always try to keep in perspective that the deeper I get into a tournament the more value my chips have, eventually getting to a point that I can put a real numeric value to them.
For many API players this might seem crazy since the tournaments are "free", but as you get deeper in API nightly tournaments or API major tournaments the closer you get to the final 2, 3 or 8 that get prizes you can literally put a real value on your chips. Most API players won't get this even still, so let me give a great example.
Back in November I played in the API Quarterly at The Tavern, eventually winning the tournament. As I got closer and closer to the final table my chips starting taking on a monetary value in my head based upon the prizes for various positions at the final table. In the end the value of my chips was a trip to the 2009 WSOP. Early on in the tournament my chips had little to no value since there was such a long way to go before the likelihood of winning was even possible, but as I moved through the tournament their value and the importance of preserving and gaining more became higher and higher until eventually I could put a real dollar value on them. To be clear, no cash is awarded at API - just prizes and sponsorships - but a prize or a sponsorship cost someone somewhere something and because of this you can assess value.
Another great example is in a Sit and Go Tournament. If the tournament started with 9 or 10 players and there are now 4 left and only 3 are paid your chips are almost worth the 3rd place cash. On Full Tilt in a $10 tournament of 10 players that would be $20 and each subsequent position adds more value to your chips based on the prize structure. Even if you have $1 in chips left and get pocket aces with 3 other players in the pot, but 2 are all in and one is a massive chip stack your $1 in chips is probably worth $20 - so do you play and risk getting knocked out to win $3 in chips or do you fold and stand a great chance of cashing? Simple - YOU FOLD. Your $1 in chips has a real value of $20 in prize money. If you go out the value of your chips is $0.
I have come to believe that in MTT's or SnG's at casinos or API that this general philosophy is one of the key differentiators between the good players and the bad players. Loose play early on in either type of tournament can cost you too much and deposition you for a run in the end. You have to be in to win and without a doubt you will need to gamble and get lucky at some point if you are going to take it down, but a little understanding about the concept I explain here will definitely take you farther.