I’m using asp.net 2.0 portal on Sitecore front end in the current project, and personalization features such as portlet drag-n-drop just won’t work unless asp.net understands that the user is logged in and can tell the difference between users.

Here’s my hack-n-slash solution: it envolves shim classes implementing IPrincipal and IIdentity, delegating everything to Sitecore. User id is returned as user name to asp.net, so that each user gets own personalization data (actually user names would also work, since they're unique). On each request, a custom processor in HttpBeginRequest pipeline (named AspnetUserSetter) puts the Sitecore principal in asp.net context.

And since I'm humble enough to allow asp.net do the rest, using default personalization database and provider - it just works. Now I wish it was easier to create custom frames around web parts.