Almost every Tuesday morning, the folks at JetBlue post their last-minute flight deals through the Twitter account @JetBlueCheeps. These are very quick flash sales, with just 25 seats on each flight for travel Saturday, returning Monday or Tuesday. Fares often start at $10 each way and the sale ends at 6 p.m. ET or when seats sell out (which they often do). Be quick on your feet. Click here to see this week's Cheeps.