Hmm. You could achieve this with the shareware program PhotoPresenter, but it won't give you Keynote's transitions, etc. You *could* create the slides in Keynote, export as images, import 'em into PhotoPresenter - but as static images (with cool transitions, timed, etc., but again - no on-slide effects).
That said, Keynote does have fairly decent timing controls - if you know exactly how long you need to keep a particular slide up, you can program it to auto-run using delays, transition lengths, etc.
That said, Keynote does have fairly decent timing controls - if you know exactly how long you need to keep a particular slide up, you can program it to auto-run using delays, transition lengths, etc.