User Interface Question

[Pete]

Wondering if anyone has any thoughts on a couple of user interface
questions.

I'm providing a popup contextual menu when the user right-clicks on a
datagrid.  I'm also providing the ability to re-order rows in a datagrid by
dragging and dropping them.  The common thread between these two functions
is that there is no on-screen indication that they exist.  Popup menus are
invisible until they are invoked and drag and drop is equally invisible
until someone initiates it.

Are there any common methods for indicating to users that features like this
are available to them?

Pete
Molly's Revenge <http://www.mollysrevenge.com>