Someone was asking the other day about raw PHP vs ASP.NET performance. I do not remember on which forum this was, but I found on JuanCri's blog a couple of simple tips that can improve the performance of your apps:

• Disable ViewState on forms that do not require it (put EnableViewState="False"). You can set this on a per-control basis for a page, or for all the pages.
• Use the output cache on pages that load data from databases.. From JuanCri's blog, set the <% @OutputCache Duration="60" VaryByParam="None" %>.