Hey, one problem with this is that if you're using migrations (which you should be), the migrations will conflict. i.e. let's say you run app a's migrations, then app b will think the schema is up to that number, which may not be good for app b.
I wrote a plugin to take care of this by recording the schema info separately for each app you want to run. http://svn.flpr.org/public/plugins/app_migrations/README
Basically you just install the plugin, and in your environment.rb file add ActiveRecord::Base.app_migration(:my_app_name)
Also if you set ActiveRecord::Base.table_name_prefix then all your tables will have a prefix so there won't be naming conflicts. With all this set up you can develop with migrations and not worry about any kind of migration or naming conflicts.
hth
Pat
