Until recently, applications that connected to CRM Online were required to use certificates as part of the authentication process. Only a limited set of certificates were supported and there was a cost to buy the certificate.
The latest (R5) version of CRM Online and the CRM 4.0 SDK includes the ability for applications to connect to the server and authenticate without using certificates. This lightweight authentication feature enables you to authenticate with CRM Online using Windows Live ID user logon information (username, password) and device information (device ID, device password).
Two new CRM 4.0 SDK samples are now available that demonstrate this new authentication technique. One sample demonstrates the basic technique while the other adds the ability to impersonate a CRM user. Through impersonation you can perform an operation in CRM on behalf of another user.
These samples can be downloaded from Code Gallery.
The latest version of the CRM 4.0 SDK can be downloaded from the Microsoft download site.