Does anyone know if there are any Gumstix products that include Analog I/O? -- I've been going through the Gumstix website but am only getting frustrated with the apparent lack of hardware datasheets...

It would be great if there were a standard product with some 12-bit DACs & ADCs.  (maybe 8 channels each?)

On a related sidenote, how difficult is it to interface custom peripheral boards with the standard Stix?  I see there are I2C capabilities on some of these models.