Do you want to implement membership,role based authorization and profile management in asp.net v1.1 applications. You can use Microsoft ASP.NET v1.1 Membership Management Component Prototype(MMCP). MMCP contains classes that allow a developer to more easily authenticate users, authorize users, and store per-user property data in a user profile. You can download this component from this location.
This is the same functionality which is going to come in ASP.NET Whidbey. But there will be few changes in this functionality in whidbey, hence during migration to whidbey you need to do few changes.
To know more on this, read these blogs
1. Scott Watermasysk blog
2. Scott blog
3. Kent Sharket blog
Rick Strahl's has done a test on storing objects in sessions and cache. He has given interesting information about this in his blog.
Fact is, When you store reference object like dataset in session or cache. It is storing a live reference of that object in session or cache. Therefore whenever you do some changes to that object, it will be reflected in session and cache objects. We can understand why it is happening in case of inproc mode for session. However interesting thing is, it is also happening when you have sessions stored in sqlserver or out of process. Though the objects are serialized in case of stateserver and sqlserver mode, it is behaving like inproc mode. To know why it is happening and to know about Rick Strahl's test on this, read his blog.