Drawing Hands and Pot Odds

[Torgen]

On the flop, you have 8/47 = 4.875-to-1 odds to make your straight on the next card. With 4-to-1 pot odds, you should call, since you need only extract a single big bet (=2 small bets) between the turn and river to make up more than the deficit.
On the turn, you have 8/46 = 4.75-to-1 odds to make your straight on the river, and 4-to-1 pot odds again. If you think the SB will bet into you (allowing you to raise), or call your bet on the river if he checks, you definitely have pot odds to call still.

(Edit: beaten to the punch several times over?)