In the case you didn' yet read Ramon Leon post on his blog:
http://onsmalltalk.com/programming/smalltalk/simple-image-based-persistence-in-squeak/

 From the post:

     "It’s a mistake to assume every application needs a relational 
database, or even a proper database at all. It’s all too common for 
developers to wield a relational database as a golden hammer that solves 
all problems, but for many applications they introduce a level of 
complexity that can making development feel like wading through a pond 
full of molasses where you spend much of your time trying to keep the 
database schema and the object schema in sync. It kills both 
productivity and fun, and god dammit, programming should be fun!

...
It shouldn’t come as a surprise that one can take a single step up the 
complexity ladder, and build simple applications that aren’t ACID 
compliant, don’t support transactions, and manage to successfully run 
most small businesses BETTER than Word and Excel while purposely not 
taking a further step and moving up to a real database which would 
introduce a level of complexity that might blow the budget and make the 
app infeasible.

No object relational mapping layer (not even Rails and ActiveRecord) can 
match the simplicity, performance, and speed of development one can get 
just using plain old objects that are kept in memory all the time"




Image as a database is my way of running my web apps for four years 
already, and I make my living of them, so I can just agree and confirm 
Ramon here!

Janko


-- 
Janko Mivšek
AIDA/Web
Smalltalk Web Application Server
http://www.aidaweb.si