diff --git a/.gitignore b/.gitignore
index 34977ee7..fc482c42 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,2 +1,3 @@
 node_modules
-.idea
\ No newline at end of file
+config/environments/*.js
+.idea
diff --git a/Makefile b/Makefile
index 92a282c7..8048c6c1 100644
--- a/Makefile
+++ b/Makefile
@@ -4,5 +4,8 @@ all:
 clean:
 	rm -rf node_modules/*
 
-check:
+config/environments/test.js: config/environments/test.js.example
+	./configure
+
+check: config/environments/test.js
 	./run_tests.sh
diff --git a/README.md b/README.md
index 80254eaa..3fc93d6e 100644
--- a/README.md
+++ b/README.md
@@ -31,19 +31,22 @@ modules. At any time just wipe out the node_modules/ directory and run
 Configure
 ---------
 
-Edit config/environments/<env>.js files
+Create a config/environments/<env>.js file (there are .example files
+to start from).
 
-Look at lib/cartodb/server_options for more on config
+Look at lib/cartodb/server_options.js for more on config
 
 Run
 ---
 
 ```
-node app.js [development | staging | production]
+node app.js <env> 
 ```
 
-Note that caches are kept in redis. If you're not seeing what
-you expect there may be out-of-sync records in there.
+Where <env> is the name of a configuration file under config/environments/.
+
+Note that caches are kept in redis. If you're not seeing what you expect
+there may be out-of-sync records in there.
 Take a look: http://redis.io/commands
 
 
diff --git a/config/environments/development.js b/config/environments/development.js.example
similarity index 100%
rename from config/environments/development.js
rename to config/environments/development.js.example
diff --git a/config/environments/production.js b/config/environments/production.js.example
similarity index 100%
rename from config/environments/production.js
rename to config/environments/production.js.example
diff --git a/config/environments/staging.js b/config/environments/staging.js.example
similarity index 100%
rename from config/environments/staging.js
rename to config/environments/staging.js.example
diff --git a/config/environments/test.js b/config/environments/test.js.example
similarity index 100%
rename from config/environments/test.js
rename to config/environments/test.js.example
diff --git a/configure b/configure
new file mode 100755
index 00000000..07d221b3
--- /dev/null
+++ b/configure
@@ -0,0 +1,38 @@
+#!/bin/sh
+
+usage() {
+  echo "Usage: $0 [OPTION]"
+  echo 
+  echo "Configuration:"
+  echo "  --help                 display this help and exit"
+  echo "  --with-pgport=NUM      access PostgreSQL server on TCP port NUM"
+}
+
+PGPORT=5432
+
+while test -n "$1"; do
+  case "$1" in
+    --help|-h)
+      usage
+      exit 0
+      ;;
+    --with-pgport=*)
+      PGPORT=`echo "$1" | cut -d= -f2`
+      ;;
+    *)
+      echo "Unknown option '$1'" >&2
+      usage >&2
+      exit 1
+  esac
+  shift
+done
+
+echo "PGPORT: $PGPORT"
+
+# TODO: allow specifying configuration settings !
+for f in config/environments/*.example; do
+  o=`dirname "$f"`/`basename "$f" .example`
+  echo "Writing $o"
+  # See http://austinmatzko.com/2008/04/26/sed-multi-line-search-and-replace/
+  sed -n "1h;1!H;\${;g;s/\(,postgres: {[^}]*port: *'\?\)[^',]*\('\?,\)/\1$PGPORT\2/;p;}" < "$f" > "$o"
+done