I always thought there was a better way to access the dom. This is a tool that allows you to use extremely simple syntax to access dom elements. It makes an object with the name of your choice (I chose "$") that contains a reference to all elements that have an id.
example:
<script> $.foo.innerHTML = "Hello world" </script>
You can even choose to use an object that already exists (I chose "document" because it makes sense)
document.foo.innerHTML = "Hello world"
If you want to live dangerously, you can even make everything global!
foo.innerHTML = "Hello world"
I like the idea of using self[a]. If we don't care about a[0] to possibly contain one element without any id, we can make this even shorter:
function(a,b,i){a=self[a]={};for(i in d=document.getElementsByTagName('*'))a[d[i].id||0]=d[i]}