Adding Analog out functionality to 9DOF- can I add another Arduino?

So I have a project using Sparkfun 9DOF with on-board Arduino Mega.

I'm getting the data from this via serial and using Max / MSP- which is where my skills really lie, and where I hope to do most of the the control need.

So far all good, the problem is I want to control at least on, maybe several Analag outputs also. A normal Arduino Mega would have this functionaility no problem, but the Sparkfun board is limited, and I don't believe it has any Analog outs I can access.

My question is how can I add to my 9dof based system to expand and provide this functionality? Can I add another Arduino that would talk to / through the 9dof?

I have the 9dof connected to a bluetooth mate for wireless connection, and am hoping to keep the as the only transmission back to the PC, rather than add a whole replication of wireless interface etc. Can I add another Arduino communicating via I2C or SPI or something else and treat it as a slave or something?

My other option may be to go back to a standard Arduino, and add the 9dof as a sensor stick or something. I already have the 9dof Razor board tho, so hoping to use is rather than replace it completely. That said- hoping someone can point out the best hardware config to achieve this, and I'm happy to start from scratch if that's what makes the most sense.

Cheers!

~Fold

You know that analog output means PWM on Arduinos?

If the related pins are not routed to headers, it depends on your skills whether you can connect wires to the controller pins. The choice of another/additional controller also depends on the purpose/load of the analog outputs. Low pass filters may be required, or power drivers, so that additional circuitry is almost inevitable.