Yeah, the reason I was thinking of using mongo is because I have to write a simple posting app (i.e. allow for blog or twitter style posts with tags) so defining a relational schema seems like overkill to me. But I can't be sure.

To the parent: thanks for the edifying comment. I do have some experience with SQL and relational DBs, but was thinking of using noSQL for some projects. Your point to thoroughly learn the relational model is well taken.