Are plywood dovetails a good solution to building something that needs to be dismantled?
Dove tail joints are not a good option for any type of furniture that you would later hope to take back apart. Dove tails are designed to make a strong and attractive joint that is meant to be permanent. 

For advice on how to create effective joints that are straight forward to put together and take apart take a study of the techniques used by kit furniture producers.







The types of fastener hardware illustrated can be purchased from a number of on-line wood worker suppliers (leevalley, mcfeelys, woodcraft, rockler). Search for terms including "cam locks", "counter top connector", and "knock-down fasteners".