I just posted a blog about IIS6 compression.  I was wondering if IIS7 compression was much different.  After some searching, here are some links I found regarding IIS7 compression.  I enabled this successfully on my IISLogs.com server and is working great.  A quick search on Technet doesn't have any IIS7 compression info.

Migrating an ASP.NET app to IIS 7
http://www.west-wind.com/WebLog/posts/6075.aspx

Changes to compression in IIS7
http://blogs.msdn.com/kjsingla/archive/2006/06/13/Changes-to-compression-in-IIS7.aspx

IIS Compression by Bernard Cheah
http://msmvps.com/blogs/bernard/archive/2004/12/01/21614.aspx

Tx,

Steve