If you’re tired of watching fares go up and down and not knowing when to buy, some new websites might be able to help. One useful feature of the new travel site Yapta.com lets you “tag” certain flights so you can track their prices. But even better, if you put in your ticketing information as soon as you’ve bought or reserved a ticket, the site will alert you if the price drops and you might be eligible for a voucher or refund.

Another way to protect yourself from volatile ticket prices is the Fare Guard from Farecast.com. For $5, you can ‘guard’ a ticket price that Farecast’s prediction engine says may rise. If the price does go up, you’ll still be able to get the lower fare, even if it doesn’t appear to be available anymore.

Finally, two other sites—Trip Stalker.com and Fare Alert.net—will automatically track prices for a specific route and email you about any fare movements.