Recieve data from Serial when loop() busy

Hello
My English is not very well.So dont blame me if I said something stupid...
I am looking for some help.When I use Arduino Mega to control some "Robotis Dynamixel" Servos,which uses a Serial packet protocol,I find that there seem to be no such things like AVR's Serial Interrupts to recieve data from servos when my Arduino is busy doing something else...So please help me...
Thank you!
windrunner

The Serial class buffers 128 characters per channel, all interrupt-driven.

You can directly use the ROBOTIS supplied embedded C Lib with Arduino. Arduino's Serial is interrupt driven already but does not work properly at 1MBps.

Check out http://support.robotis.com

BTW .
Robotis embedded c lib uses

Serial line ( i.e pin 0 & 1 ) for TTL /RS485 communication.