For an good introduction to Service Bus and Access Control check out the following link
http://www.microsoft.com/windowsazure/appfabric/#appfablabs
Windows Azure AppFabric SDK (Sept 2010 UPDATE) download can be found at
http://www.microsoft.com/downloads/en/details.aspx?FamilyID=39856a03-1490-4283-908f-c8bf0bfad8a5&displaylang=en
32bit and 64bit SDK versions are available. Also, code samples for VB & C# and AppFabricDocs. The docs download is blocked for security, so once you have downloaded the docs, right click the docs file, select properties, click unblock then click Apply and OK. The docs can be read offline.
Windows Azure AppFabric Labs (Aug 2010 UPDATE) download can be found at
http://www.microsoft.com/downloads/en/details.aspx?FamilyID=D89640FC-C552-446E-AEAD-B1E0D940F31B
There are 2 files to download, the Service Bus.config.txt file and release notes(html) file. There is no SDK to download here, you need to download and install the win. Azure AppFabric SDK.
