Upgrading to an iPhone 5, will I lose my contacts?

Okay so I have an iPhone 3G and I'm upgrading to the iPhone 5 today. Do your contacts from the old phone show up on the new phone? I know there's a new SIM card for the iPhone. It is much smaller. I looked on iTunes to see if my contacts every synced into it, but iTunes doesn't even have an address book.So. Should I write down all 105 of my contacts on a piece of paper? Just to be safe? Is there a faster way to do this? You might say use the address book on the mac but I do not have a mac. Please help, especially if you know from experience!

If you back up your phone to iTunes than your contacts will be stored there even though it does not have an address book.

Do you have icloud on your current phone? If so just turn it on, click yes to backup, and you are done… On your new phone you will turn on icloud and it will ask if you want everything copied automatically… Its slick. You can use itunes also as suggested above.

Look at http://www.smartphonemoviles.com/