Optimising a PDF for on screen viewing

[Skooter]

I'm capturing images with a profile that specified .png images at 96dpi for online, and .jpg at 300dpi for print. Apart from a bug associated with resizing the print size for the print format - I am able to resize images how I want them for the printed page.
Only trouble is the size of the PDFs come out quite large (I realise there is also an outstanding issue to do with PNG images included in PDF output) - which is not a problem if a PDF is primarily meant to be printed - but I obviously don't want to distribute large size PDFs to users.
So what's the best way to optimise a PDF for on-screen viewing? I tried setting the Medium to non-print, but the online images then need adjusting if they are to fit on the printed page. It would be good if you could set an 'ignore print format' flag in the target, but still have the print size be honoured. Asking too much?

[Skooter]

(Re: Previous post) Or rather "Ignore Print DPI" or be able override it with, say, 96 dpi, but still keep the print size you set for the image.