Simple trie implementation in JavaScript
Well, first of all, my optimization is an overhaul of your method. The concept is still tries. But I went for the JS route for several reasons:


We're in JavaScript. Linked lists in C would be like Arrays/Objects in JS. Since we have them available, why not use them instead?
In tries, you use a key for each entry. You'd have to loop over and find it when using linked lists or arrays. In JS, we have objects that are key-value pairs, which make it a bit easier to implement.
Performance is a bit better, except on Opera browsers. Performance may be due to the lesser loops and property access.
The code is shorter


The structure:

{
  "t": {
    "key": "t",
    "r": {
      "key": "r",
      "u": {
        "key": "u",
        "e": {
          "key": "e",
          "value": "yes",
          "name": "true"
        },
        "c": {
          "key": "c",
          "k": {
            "key": "k",
            "value": "vehicle",
            "name": "truck"
          }
        }
      },
      "o": {
        "key": "o",
        "w": {
          "key": "w",
          "e": {
            "key": "e",
            "l": {
              "key": "l",
              "value": "dig",
              "name": "trowel"
            }
          }
        }
      }
    }
  },
  "h": {
    "key": "h",
    "a": {
      "key": "a",
      "t": {
        "key": "t",
        "value": "head",
        "name": "hat"
      },
      "l": {
        "key": "l",
        "t": {
          "key": "t",
          "value": "hold it",
          "name": "halt"
        }
      },
      "m": {
        "key": "m",
        "value": "pig",
        "name": "ham",
        "m": {
          "key": "m",
          "e": {
            "key": "e",
            "r": {
              "key": "r",
              "value": "nail",
              "name": "hammer"
            }
          }
        }
      }
    }
  }
}


As for the code that operates this, notes are on the comments:

function Trie(key) {
  this.key = key;
  this.value;
  //children are merged with this object since collision is minimal
}

Trie.prototype.put = function (name, value) {

  var node = this,
    nameLength = name.length,
    i = 0,
    currentLetter;

  //the only major change is this single loop which zips through the collection
  //if the node exists, make it current and proceed
  //if not, we create it, make it current and proceed
  for (i = 0; i &lt; nameLength; i++) {
    currentLetter = name[i];
    node = node[currentLetter] || (node[currentLetter] = new Trie(currentLetter));
  }

  node.value = value;
  node.name = name;

};

Trie.prototype.get = function (name) {

  var node = this,
    nameLength = name.length,
    i, node;

  //same idea, zip through the collection
  //in this case we break if we hit a dead end
  for (i = 0; i &lt; nameLength; i++) {
    if (!(node = node[name[i]])) break;
  }

  //only when the loop went over all letters will we find a value
  //if not, well, we don't find anything
  return (i === nameLength) ? node.value : 'not found';
};