I don't think you're being daft. It's a good line of thinking, even if it may not be contributory to the
PR of a page/site - I'm pretty sure there must be an element of
PR which comes from user interaction and simply not just algorithms and it's various elements.
I have always thought that your listing being popular in search results for a particular keyword, i.e. a search for 'free' and a site at position 8 was clicked more frequently than a result higher in the rankings, would be recorded and used for allocating
PR for the next Google update. Again, it might not be the case at all, but it might be!
I have thought on the same lines as you and would be interested to know if others have too.
On the subject on making sure your visitors use the toolbar too, you would need to make sure they have downloaded that particular version of it (the one that sends info to google) and that the number of visits they make to your competitiors are less than your own, otherwise you'd be shooting yourself in the foot
One way to test this would be to find a site or page with a very low
PR, get everyone you know with the toolbar to make it their start page and visit it frequently and see what affect, if any, it has to the
PR the following Google update.
I have one site (
www.lowestoftonline.com) where it ranks at number 2 for a search for 'Lowestoft' even though the rank 3 has a higher
PR and many, many more backward links to it. It's domain (
www.lowestoft.net) obviously has the search term as the full domain too, if that counts?
(please don't hit me with spam reports, it's a not-for-profit site and only offers interest to those who live or have lived in Lowestoft, but it's a good example of Google's antics)
Cheers,