Add/edit panel that slides up from button

I need to display a pretty simple data entry/edit form, two fields and a save button. I don't like the idea of using a modal dialog as it appears in the middle of the screen, far removed from the button clicked on to show the dialog.

What I am thinking is if you click the button to add a new category... the form slides up from seemingly behind the button. You only have to move your mouse a short distance, or none at all if the first field is selected. You enter or edit the category name and description, hit save, a confirmation or validation error is displayed at the top of the form, and if successful, after a few seconds, slides back down out of site.

Anyone seen or created something like this?