I am using the beamer document class in latex to make a presentation. I will have a number of back up slides which are there for offline viewing, reference etc. Beamer has a feature that shows the progress through the presentation as {page#}/{total pages} on each slide. I would really like it if {total pages} was equivalent to my total number of pages w/out counting the back up slides (I don't want to discourage my audience on the first page!). Does anyone know how this can be done?