If you brought a laptop, you can monitor your accounts from your hotel room or even the pool. Make sure the Internet connection is secure (did you have to enter a password to get online?) and check your transaction records.
Under no circumstances, says Sileo, should you do this at a shared or public computer in a hotel's lobby or business center. "The instances of tracking software on public computers are so high it's like playing Russian roulette," he says. If a public computer is the only one available to you, consider calling your issuers instead to verify you're the only one using your accounts.