communication methods

[gaurav.p]

hey guys,
 
well i have been doing some research on methods of implementing wireless communication between arduinos(or it can be any avr compatible borad)

• RF(well the cheapest of them)
• XBee or Zigbee(very popular and are also RF modules)

• ethernet(quite tough for a begineer)
• Bluetooth(this also is for a imtermediate user)

• I Need More...........

what are the con's of RF.
please can anybody compare the above methods and tell the pro's/con's of the mentioned methods.
i m quite fascinated by RF since u can get the transmitters at dirt cheap here in India.all new methods for communication are a welcome at these post.please correct me if am wrong anywhere.hope to see quick replies.

Regards,
Gaurav