I know I'm just a contrib developer, but as a seasoned app developer I thought I'd put in my 2 cents. If you're talking about object caching where in 90% of the cases the objects live in the database, I wonder whether this kind of caching would have a better payoff than just increasing the memory caching done by the DB engine (mysql,etc). It doesn't strike me as a big payoff for the code that it would take too achieve. I'd recommend general caching drupal caching API's should be restricted to "rendered" objects, such as the output of a block, a view, or a menu. Then you save the expensive rendering process. If you're just talking about object data, let the database engines do the caching. Of course it does make sense to cache XMLRPC call results and other expensive data gets. It seems really odd to talk about caching nodes in a database, when nodes and users are in a database to begin with? Dave