caching - Ask the browser to cache our images（ ASP.NET/IIS )
I just ran Google's Page Speed application against our site and one of the recommendations was to Leverage browser caching. Expanding this revealed the following:
The following cacheable resources have a short freshness lifetime: Specify an expiration at least one week in the future for the following resources:
<a long list of images
How do I go about lengthening the "freshness lifetime" of particular images?
It's an ASP.NET project running on IIS7.5