Thank you for your comments, Cheryl.  In the case of our firm, and in light of the close relationship with some of our local and foreign clients (with operations in Colombia), we are often asked (maybe 2-3 times a year) to provide a seconded attorney for X days a week at a set rate, typically to fill in for a temporary vacancy (e.g. a maternity leave) or in other cases where the client wants to run a pilot program to explore the possibility of creating a new position (e.g. Patent Counsel).  Most of these programs run for about 6 months and the associate continues to be a full-time employee of the firm.  We normally do not allow the associate to completely disconnect from firm activities and responsibilities, but balancing priorities is often tough.  The upsides I mentioned in my initial e-mail.  

Our firm considers secondments an excellent opportunity to get closer to clients, really understand their business and develop more sustainable relationships.  Associates returning from these projects also bring a new skill set and understanding of company culture that only a corporate setting can create, enriching professional and personal development.  However, there is some (perceived) downside: potential loss of the associate to the client and consequent loss of business; conflict issues; and potential reputational impact to the firm if the secondment does not work out (merited or not).  I would be interested in hearing about positive and negative experiences, as well as tips and best practices on how to manage a secondment, including boundaries, expectations and scope.  Thank you!