Added an example of capistrano deployment recipes for deploying to a remote web host running Phusion Passenger (aka mod_rails), which is probably the easiest Rails deployment environment to configure.

lib/tasks/database.rake

@@ -0,0 +1,27 @@
+require 'rake'
+
+namespace :db do
+  desc "Dump the current SQLite3 or MySQL database to a sql file" 
+  task :dump_sql do
+    load 'config/environment.rb'
+    abcs = ActiveRecord::Base.configurations
+    case abcs[RAILS_ENV]["adapter"]
+    when 'mysql'
+      ActiveRecord::Base.establish_connection(abcs[RAILS_ENV])
+      File.open("db/#{RAILS_ENV}_data.sql", "w+") do |f|
+        if abcs[RAILS_ENV]["password"].blank?
+          f << `mysqldump -h #{abcs[RAILS_ENV]["host"]} -u #{abcs[RAILS_ENV]["username"]} #{abcs[RAILS_ENV]["database"]}`
+        else
+          f << `mysqldump -h #{abcs[RAILS_ENV]["host"]} -u #{abcs[RAILS_ENV]["username"]} -p#{abcs[RAILS_ENV]["password"]} #{abcs[RAILS_ENV]["database"]}`
+        end
+      end
+    when 'sqlite3'
+      ActiveRecord::Base.establish_connection(abcs[RAILS_ENV])
+      File.open("db/#{RAILS_ENV}_data.sql", "w+") do |f|
+        f << `sqlite3  #{abcs[RAILS_ENV]["database"]} .dump`
+      end
+    else
+      raise "Task not supported by '#{abcs[RAILS_ENV]['adapter']}'" 
+    end
+  end
+end