Passing session data between ASP.NET Applications

We have several ASP.NET applications deployed to a few servers. Is there a standard way to reuse session data or some other method to not require users to log in to the next application when moving from application to application if they've already authenticated? I'm hoping there's a best practices way of doing this that you guys know about. I feel like there should be something easy that I'm missing.

Thanks.

Edit: To be be more clear, the main info in the session that I'd like to pass is the authenticated userid, but possibly some other session variables as well.

you could implement a single-signon strategy for your applications.

http://aspalliance.com/1545_Understanding_Single_SignOn_in_ASPNET_20.all

http://blah.winsmarts.com/2006/05/19/aspnet-20-implementing-single-sign-on-sso-with-membership-api.aspx

http://johndyer.name/post/2005/12/Single-SignOn-with-ASPNET-Membership-and-WebServices.aspx

http://msdn.microsoft.com/en-us/library/ms972971.aspx

Single Sign On (SSO)

http://msdn.microsoft.com/en-us/library/ms972971.aspx

For the session check this: http://www.codeproject.com/KB/aspnet/Sharing_session_state.aspx

Complement with this so the cookie is shared: http://mgrzyb.blogspot.com/2007/12/aspnet-and-subdomains.html