Plugins - extended model generator
Add to favoritesRuby on Rails plugin for model generation
Usage
ruby script/generate my_model User name:string:limit_48:null_false:default_username pass:string:limit_15
Options
null_true or null_false
default_string
limit_integer
precision_integer
scale_integer
autoincrement_true or autoincrement_false
Install
ruby script/plugin install http://extended-model-generator.googlecode.com/svn/trunk/my_model/
http://code.google.com/p/extended-model-generator/
http://extended-model-generator.googlecode.com/svn/trunk/
Rails' (MIT)
Misc. Enhancements

ares, ever tried migrations?
Cannot understand exactly what the plugin offers? Then try the standard migration.
ever heard of migrations?