Reading from http://developer.android.com/guide/topics/wireless/bluetooth.html,
The current Android Bluetooth API's require devices to be paired before an RFCOMM connection can be established. (Pairing is automatically performed when you initiate an encrypted connection with the Bluetooth APIs.)
However, to my knowledge, the Bluetooth protocol allows .vcf (vCard) files to be sent without having paired two devices. This is what makes Bluejacking possible on older phones like Sony Ericsson k7** series, Nokia 63** series etc.
In the interests of writing an android bluejacking application I would like to be able to send vCard files from Android without having to first pair with the device. Does anyone know if this is possible?