well, here is what I am doing

a) I use blowery for http compression.- For most new browsers, http compression is a MUST for everyone. You will have to check if all your modules work well with it. You can always exclude URL paths from compression

b) I use DSLocalizator and its optimization features.- As many people know, I included some optimization features inside DSLocalizator, so you can use it to optimize your site without the need to localize anything

1. Enable SQLViewState.- Sometimes and depending of what modules do you have, you asp.net engine will generate big viewstate information directly on the response sent to the requesting user. DSLocalizator can store that info inside your SQL server and avoid sending extra data to the final user. DSLocalizator can also enable/disable this feature per page (or per site) so you can avoid using it when a page don't need it.
2. Enable WhiteSpaceRemover.- DSLocalizator includes a feature that could remove your html spaces (Cr,  tab, etc) to reduce the final response. The size of spaces from you page may depend of the kind of modules and content you have in your site.