What is the best data structure to use for a phone book on a mobile device

If you were to implement a phone book where each entry will be first name, last name and phone number of your contacts, what would be the best data structure for this? The phone book will give the user the option to sort by first n开发者_C百科ame. The other caveat is that this app will run on a mobile device.

Use MS SQL Compact Edition.

I'd go with a SQLITE database, personally. There are lots of libraries to use them across many languages and they're fairly common for things such as this.