Hi, I was thinking that it might be useful to cache the marshalled version of an object with the object itself. If you were writing some code that had to marshal objects repeatedly and had a chance of remarshalling the same thing twice, this could save some time. I admit, this might just be a symptom of bad coding, but I've run into it recently. For example, if you had an array with two or more references to the same large object and you wanted to marshal the array, this could be useful. This feature could be togglable: Marshal.enable_caching and Marshal.disable_caching. Does this seem useful to anyone? Emil