Change your template to be something like:

<script id="item-display-template" type="text/html">
  <li>
    <div class="item-display-container" data-itemid="${Id}">
        <p>${SomeData1} .... ${SomeData2} etc....</p>
        <a class="editrow">Edit This Item</a>
    </div>
  </li>
</script>

By placing the id on the div.item-display-container you make it very easy to add other functionality that can easily access that same id, say like a delete link.

Then on the <ul> element you are inserting these <li> element in to do this:

$( ul ).delegate( .editrow , click ,function(e) {
    e.preventDefault();
    var id = parseInt($(this).parents( .item-display-container ).attr( data-itemid ), 10);
    editRow(id);
});

I would use a data attribute, like this:

<script id="item-display-template"> type="text/html">
  <li>
    <div class="item-display-container">
        <p>${SomeData1} .... ${SomeData2} etc....</p>
        <a class="edit" href="#" data-id="${Id}">Edit This Item</a>
    </div>
  </li>
</script>

Then a .live() or .delegate() handler, like this:

$("a.edit").live("click", function() {
  var id = $(this).attr("data-id");
  //use the id
});

Or .delegate():

$("#myUL").delegate("a.edit", "click", function() {
  var id = $(this).attr("data-id");
  //use the id
});

As a side note: In jQuery 1.4.3+ coming out later this week, you can use .data() like this:

var id = $(this).data("id");
//or:
var id = $.data(this, "id");

It ll fall back to the data-id attribute to get a value if there isn t one in it s data collection.

No, you can t do that, but you could stash the "id" in some HTML attribute — like, say, the "id" attribute.

(Well actually you could have the template generate in-line Javascript blocks to do it, but that seems terribly ugly.)

Rather than using old-fashioned "onclick" to bind your event handlers, you could give the <a> elements the "id" value (with some alpha prefix, if the "id" value is numeric) and also a "class" value. Then, after expanding the template from your jQuery code, you could bind event handlers. Alternatively you could pre-bind event handlers with .delegate() (edit like in @Nick s answer.)

<script id="item-display-template"> type="text/html">
  <li>
    <div class="item-display-container">
        <p>${SomeData1} .... ${SomeData2} etc....</p>
        <a id="id_${Id}" class="link-for-edit">Edit This Item</a>
    </div>
  </li>
</script>

var eventEdit = function(ev) {
    //...
    var id = $(this).attr( id ).split( _ );
};

var items = $( #item-display-template ).tmpl(data);

$(items).find( a.link-for-edit ).bind( click , eventEdit);
$(items).appendTo( ul );

jQuery templates has jQuery.tmplItem() function. Using this, you can access the data object you have used to render the template. So it s not necessary to duplicate the data at the DOM level. You can use it like this:

<script id="item-display-template" type="text/html">
  <li>
    <div class="item-display-container">
        <p>${SomeData1} .... ${SomeData2} etc....</p>
        <a class="editrow">Edit This Item</a>
    </div>
  </li>
</script>

Then in the "Edit..." click handler you access template s underlaying data to get the Id value:

$( ul ).delegate( .editrow , click ,function(e) {
    e.preventDefault();
    var id = $(this).tmplItem().data.Id;
    editRow(id);
});

JQuery templates already solve this problem for you with the tmplItem function. You can use the clicked element to associate the data that it is bound to:

$("#item-display-template").tmpl(clientData).appendTo("ul"); 

$("li a").click(function() {
    var tmplItem = $(this).tmplItem();
    alert(tmplItem.data.id);
});

See the full working example I did here

....and a related question here for another example.