My situation was a little different (Score 2, Interesting)

I had 5 or so years in the field, than left in 2002 for a three year "sabatical", semi-voluntary unemployment. I took a small contract gig, 1 or 2 months doing some analysis, played with Linux kernel dev for a bit, expermented with some OSS development, etc. When the time came to go back to work, I listed it on my resume just like any other job:

Sabbatical
January 2002 - September 2004 Paris, France

I maintained my skill set by working on small and personal projects, expanding my knowledge of networking, software development and system administration.

• Develop requirements, model, and prototype an EDI system to enable Medicaid submissions under HIPAA.
• Explore advanced system administration, network administration, kernel and device driver development under Linux and FreeBSD.
• Develop several personal database solutions using MySQL, JDBC, Servlets and XML/XSLT.
• Implement many of the "Gang of Four" design patterns in Java.

And had no problems or negative remarks about my time off. Closer to your situation, when I was finishing grad school and needed some technical experience, I included the grad asst I worked in the identical manner. Once I had some real experience that entry dropped off, but it worked at the time.