added cartesian example...

cartesian/cartesian.txt

@@ -0,0 +1,35 @@
+# ./pyspark
+Python 2.6.9 (unknown, Sep  9 2014, 15:05:12)
+...
+Welcome to
+      ____              __
+     / __/__  ___ _____/ /__
+    _\ \/ _ \/ _ `/ __/  '_/
+   /__ / .__/\_,_/_/ /_/\_\   version 1.3.0
+      /_/
+
+Using Python version 2.6.9 (unknown, Sep  9 2014 15:05:12)
+SparkContext available as sc, SQLContext available as sqlCtx.
+>>> a = [('k1','v1'), ('k2', 'v2')]
+>>> a
+[('k1', 'v1'), ('k2', 'v2')]
+>>> b = [('k3','v3'), ('k4', 'v4'), ('k5', 'v5') ]
+>>> b
+[('k3', 'v3'), ('k4', 'v4'), ('k5', 'v5')]
+>>> rdd1= sc.parallelize(a)
+>>> rdd1.collect()
+[('k1', 'v1'), ('k2', 'v2')]
+>>> rdd2= sc.parallelize(b)
+>>> rdd2.collect()
+[('k3', 'v3'), ('k4', 'v4'), ('k5', 'v5')]
+>>> rdd3 = rdd1.cartesian(rdd2)
+>>> rdd3.collect()
+[
+ (('k1', 'v1'), ('k3', 'v3')), 
+ (('k1', 'v1'), ('k4', 'v4')), 
+ (('k1', 'v1'), ('k5', 'v5')), 
+ (('k2', 'v2'), ('k3', 'v3')), 
+ (('k2', 'v2'), ('k4', 'v4')), 
+ (('k2', 'v2'), ('k5', 'v5'))
+]
+>>>