How do I transfer contacts from Android to iPhone?
There is a physical way to transfer contacts and a software method. The physical method works if your Android phone takes a Micro SIM and the iPhone you're transferring to is an iPhone 4S or iPhone 4. If you're transferring to an iPhone 3G or 3 - you'll need a full size SIM for compatibility.
First save all contacts on the Android phone to its SIM. Next, insert the SIM into your iPhone, taking care not to mislay the iPhone's SIM. Finally, go to Settings and choose "Mail, Contacts, Calendars" and tap "Import SIM Contacts". When the operation has finished, you can replace iPhone's SIM card.
The software method works on all iPhones but is, in our long experience working across multiple platforms, a bit unpredictable.
Just as Apple's contacts and sharing tools are locked up behind a walled garden (MobileMe previously, now iButt) - Android's contacts are Google compatible. So, the first step is to get the contact on your Android phone into Google's butt. For this, you'll need a GMail address and login.
Next, go to Settings on your Android phone and choose "Accounts and Sync" or similar. Enter your GMail account details and enable synchronisation. Your phone contacts and Google Contacts should now synchronise.
To import the contacts on your iPhone, go to Settings > Mail, Contacts, Calendars and add your GMail account. Make sure Contacts are enabled for the account.