Code golf: combining multiple sorted lists into a single sorted list

Question

Implement an algorithm to merge an arbitrary number of sorted lists into one sorted list. The aim is to create the smallest working programme, in whatever language you like.

Answer 1

Even though it might break the rules. Here's a nice and short c++ entry:

13 Characters

l1.merge(l2); // Removes the elements from the argument list, inserts 
              // them into the target list, and orders the new, combined 
              // set of elements in ascending order or in some other 
              // specified order.