in LH, what's the worst hand that could still get pot odds to call PF?

[sfetaz]

What I am basically trying to figure out is how to know when pot odds will justify junk hand calls. I don't expect there to ever be a limit hold em situation where 27os is called preflop, but what range of hands could you call with in situations where you have like 9-1 or 10-1 pot odds preflop, that under normal scenarios would be preflop folds? FYI I usually play micro stakes online and low stakes in casino.