REST
What does REST mean to you and your company? It is better to make this decision well in advance before you build an enterprise system.
I have listed some good articles on REST which I felt gives a better idea on this architecture
http://www.xfront.com/REST-Web-Services.html
http://www.subbu.org/weblogs/main/2007/10/soapy_rest.html
http://rest.blueoxen.net/cgi-bin/wiki.pl?RestTriangle