How can you customize the numbers in an ordered list?

How can I left-align the numbers in an ordered list?

1.  an item
// skip some items for brevity 
9.  another item
10. notice the 1 is under the 9, and the item contents also line up

Change the character after the number in an ordered list?

1) an item

Also is there a CSS solution to change from numbers to alphabetic/roman lists instead of using the type attribute on the ol element.

I am mostly interested in answers that work on Firefox 3.

This is the solution I have working in Firefox 3, Opera and Google Chrome. The list still displays in IE7 (but without the close bracket and left align numbers):

ol {
  counter-reset: item;
  margin-left: 0;
  padding-left: 0;
}
li {
  display: block;
  margin-bottom: .5em;
  margin-left: 2em;
}
li::before {
  display: inline-block;
  content: counter(item) ") ";
  counter-increment: item;
  width: 2em;
  margin-left: -2em;
}

<ol>
  <li>One</li>
  <li>Two</li>
  <li>Three</li>
  <li>Four</li>
  <li>Five</li>
  <li>Six</li>
  <li>Seven</li>
  <li>Eight</li>
  <li>Nine<br>Items</li>
  <li>Ten<br>Items</li>
</ol>

EDIT: Included multiple line fix by strager

Also is there a CSS solution to change from numbers to alphabetic/roman lists instead of using the type attribute on the ol element.

Refer to list-style-type CSS property. Or when using counters the second argument accepts a list-style-type value. For example the following will use upper roman:

li::before {
  content: counter(item, upper-roman) ") ";
  counter-increment: item;
/* ... */