The Google Nexus One. Based on Android, it's superior to any other device, including the iPhone and anything Blackberry can offer. The device does all those things you mentioned. It's a GSM phone, so it will work on 99?f the planet.
The Nexus One's T-Mobile version has the frequencies to work with Digitel's cell service in Venezuela, including their 3G data.
The phone comes SIM unlocked from the manufacturer, so all she needs to do it slip in the SIM card and she's ready to go.
Since she'll be working in a foreign country, she shouldn't get service in the US then use roaming in South America. This will cost thousands of dollars each month. She needs to use a GSM phone, and get service down there. Far cheaper.
The nice thing is that the phone has integrated Google apps, so it stays in sync with her Gmail, contacts and calendar. No special software needed.
The Nexus isn't cheap, but it is a terrific phone. She can use it with T-Mobile's service when she returns. In fact, if the buys the phone outright, she can get a no-contract plan from T-Mo, which are very reasonable.
I've had mine since March. Simply terrific, best phone I've ever owned.