How to easily transfer contacts from any (Bluetooth capable) phone to an Android phone

There're at least a thousand and one ways to do this, but imho the bluetooth method is the most simple. On your old phone open the phonebook, select all entries and send them to the new phone via Bluetooth. On the new phone you'll get a notification about each received contact (*.vcf file), click each to import them into the Android phonebook. This worked for me during a Nokia N95 -> Google Galaxy Nexus migration.