-j parameter added to rails new command.
Please discuss first on rails core mailing list if We really should provide that as an option. One could argue for example we should Allow rspec to be given to test framework option using the same argument, which just complicates maintenance on rails side.
this discussion about this is here: http://groups.google.com/group/rubyonrails-core/browse_thread/thread/b6ea0b3f5fc25863
Xavier Noria suggestions added! Guides #16, parts 27-29.