htomasso suggested in a comment to my last blog entry that I should take a look at NHibernate for my object/relational mapping needs. I remember learning about object oriented databases, but this seems solve the problem as well, i.e., persisting objects to a database (for retrieval).
My current problem is storing data from a hierarchal DTO model to a database. This data is used to calculate summary statistics, doing trend analysis, profiling, and debugging. But the DTOs are never actually retrieved back as DTOs from the database. So, although it looked promising initially (simplified the storing part), I think that O/R libraries are not suited for this scenario.
I did some web-research to find out what was being said as to when O/R libraries apply, but could not find any definite guidelines :(