Concatenate 10,000 strings: ASPX (C#, StringBuilder)
<%@ Page language="C#" debug="true" %>
<%
  System.Int32 i=0;int j=0;long start=System.DateTime.Now.Ticks;
  System.Text.StringBuilder s=new System.Text.StringBuilder(10000);
  this.Response.Write("Start <br>");
  for (j=0;j<10;j++) {s.Remove(0,s.Length);
  for (i=0;i<nCount;i++) {s.Append(i.ToString());};}
  this.Response.Write("Done "+((System.DateTime.Now.Ticks-start)/
    10000000.0/10).ToString()+"s "+s.ToString().Length.ToString()+"
"+i.ToString()+"<br>");
%>
On 850 MHz PIII: 0.026 seconds