David Gewirtz just posted a nice article/review/guide this morning on the use of the Obi110/100 with Google Voice. I thought the article is well-written and very easy for new Obi users to understand and use.
Link: http://www.zdnet.com/blog/government/google-voice-a-cheapskates-guide-to-cheap-voip/10500?tag=nl.e539
Good catch. And a pretty nice series of basic articles about Google voice
NB