Google Chat

By default, your chat list will be sorted by the people with whom you communicate most often. However, you also have the option of changing to alphabetical sort order.

In Gmail:

1. Click Options from the bottom of your chat list.
2. Under Show in chat list: click All contacts or Top 250.

In iGoogle and orkut:

1. Click Actions from the bottom of your chat list.
2. Under Sort chat list: click Alphabetical.

You can change this back to popularity by selecting Most Popular instead.

If you would like more contacts to show, you can always resize your chat list.