contacts when taking unlocked iPhone abroad

[elguero]

Hello, very simple question. I will be taking my unlocked iPhone abroad for the first time and will be using a local prepaid SIM card while on my trip. My question is about the nature of contacts on the phone.
If I start saving the local phone numbers of people I will visit now, will they (and all of my current contacts) still be on my phone when I put in a foreign SIM? Or will a virgin SIM have an empty contact list? I'd hate to have to do it all twice..
If there is a setting where I can save everything onto the phone before pulling the SIM, please let me know.
I also wonder if I'd have to enter the phone numbers with their full international code, but that would be less of a pain than adding them all again.
Thanks!

 

[r6girl]

Contact information is not stored on the SIM card - it's stored in the iPhone. As long as you sync your iPhone regularly with your computer (or use MobileMe or a similar service), you'll always have a back-up of your contacts on your computer.

When you use another SIM card, you may need to adjust your contact's phone numbers to include the appropriate country prefix. This is what I had to do when I used pre-paid SIM cards in my unlocked iPhone while in Spain earlier this year. I also had to enter APN settings (provided by the carrier) in order to get internet connectivity through the cellular networks.