Pot Odds...preflop?

[cgwahl]

This might seem like a very basic question, but while watching a poker tournament on TV some nights ago it got me wondering since one of the announcers kept saying such and such was getting great pot odds and had to call even if their particular cards weren't exactly great. Granted, the announcer may have been a moron and just liked using buzz words (incorrectly), but like I said...it got me wondering.

For instance, person raises and you get 2 to 1 pot odds if you call with 10 5 offsuit.

How do you correctly figure pot odds preflop? Is this something that you only really see in no limit or can this be used in limit as well? Do you just go by how the odds of getting certain hands on the flop based on what your hole cards are then base what your implied odds are when the flop and so on come?

Because right now, since I'm a novice, I just base whether or not I go into a hand on what the cards I have and where I'm at and stuff. Granted, I'll still sometimes go into a hand if there is a lot of money in the pot as is and I can get in cheap, but pot odds preflop is just something I never even considered before. And if it was at all mentioned in any of the books I have read so far I must have missed it.

Thanks to whomever answers.