I’ve released WP Grins, a clickable smilies hack for WordPress. This lets you easily add a row of smilies to the post form in the admin area, and/or the comment form on your blog.

Like the Quicktags, the smiley inserting is cursor-aware. It inserts the smiley tag where the cursor is as long as your browser supports it (IE and Mozilla are fine).

You can grab it from my WordPress Hacks page.