WordPress Themes Development Question:

Sometimes it is necessary to know the ID of a particular Post, Page, Category, Tag, Link, Link Category, or User. To determine that ID, use one of these method:
Look in your browser status bar for the ID:
Visit the related ‘Edit’ screen in your Administration Panel. For instance in the case of Posts visit Posts->Edit, for Pages visit Pages->Edit, and for Categories visit Posts->Categories.
Now hover your mouse over the ‘item’ you need the ID. In the case of Pages, hover over that particular Page’s title in the Title column and for Categories hover over the Categories Name in the Name column.
Look at the status bar (at the bottom of your browser) and the you will find at the end of the line something like “post=123″ or “cat_ID=67″. In these cases, 123 is the Page ID, and 67 is the Category ID.
Install a plugin:
Install and activate Reveal IDs for WP Admin, Simply Show IDs, or ShowID for Post/Page/Category/Tag/Comment.
Find the ID displayed with each item.