[development] Autocomplete For A "Select" Widget

I'm looking at using autocomplete for contacts stored in CiviCRM. Implementing basic autocomplete using the standard Drupal hook was pretty simple: just search the CRM store for a contacts "display name" via the autocomplete handler. But there's a problem with how the standard handler works: display names are not unique. What I probably *need* to do is this: use the autocomplete field to populate a "select" widget that uses the display name as the label, and the unique numerical contact_id as the key. Before I start looking into implementing this myself: have any of you implemented this kind of widget? Or do you have advice how best to do this? Thanks, Rob Rob Thorne Torenware Networks http://www.torenware.com