If I've made modifications to an object attached to a session is there any way to easily get the "old" version of the object?

A possible way I've thought of for doing this include evicting the object before making the modifications and keeping a reference to it for comparison later but I was wondering if there is any better/easier mechanism.

I think you need to define a history table in your database design.

This might help as well:
http://www.hibernate.org/195.html

Best regards
Sven

In exactly what I'm after in this case.

I don't really want to keep a record of historical values. Just to compare what's changed between the in-memory copy of the object and the version that's currently persisted to the database.