Adding Web service API to Michael Hartl's completed Rails Tutorial
Thank you Michael Hartl, the tutorial is awesome!

Can anyone please advise of the next steps to expose some functionality in the form of a service API. in particular, I am interested in having an iPhone client and was wondering of the best way (most secure, fast, clean) to accomplish that. Is it advisable to introduce a token that would be passed with every service call? what I can add to the current authentication/session implementation to mirror this on the iPhone side? (i.e, carry a "forever" session, and secure API calls). 

Thank you! any help is much appreciated! 
Adding Web service API to Michael Hartl's completed Rails Tutorial
===

Thank you Michael Hartl, the tutorial is awesome!

Can anyone please advise of the next steps to expose some functionality in the form of a service API. in particular, I am interested in having an iPhone client and was wondering of the best way (most secure, fast, clean) to accomplish that. Is it advisable to introduce a token that would be passed with every service call? what I can add to the current authentication/session implementation to mirror this on the iPhone side? (i.e, carry a "forever" session, and secure API calls). 

Thank you! any help is much appreciated! 