http://www.javascriptcity.com/scripts/local/sscroll1.htm

<SCRIPT language="JavaScript">
<!--
var wait = 50   //sleep time until next letter (milliseconds)
var message = new Array()
message[0] = "Welcome to my homepage...          "
message[1] = "If you have some good suggestions or wishes, then feel free
to e-mail me.         "
message[2] = "my mail address: me@me.com          "
var msgs = 2   //Number of message (0 is first)

var temp = ""  //Do not modify these... (recommended)
var curmsg = 0
var a = 0
var counter = 0

function typew()
{
a = a + 1
check()
window.status = message[curmsg].substring(0, a)
if(a == message[curmsg].length + 5)
{
curmsg = curmsg + 1
a = 0
}
if(curmsg > msgs)
{
curmsg = 0 }
counter = setTimeout("typew()", wait)
}
function check()
{
if(a <= message[curmsg].length)
{
if(message[curmsg].substring(a, a + 1) == "")
{
a = a + 1
check()
}
}
}
typew();
//-->
</SCRIPT>