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

VB.NET (2008) 185 chars

Accepts List(Of List(Of Byte))

Function s(i)

    s=New List(Of Byte)

    Dim m,c
    Dim N=Nothing

    Do
        m=N
        For Each l In i:
            If l.Count AndAlso(l(0)N Then s.Add(m):c.Remove(m)       

    Loop Until m=N

End Function