robzilla - 12:46 pm on Oct 29, 2013 (gmt 0)
site:mysite.com shows shortest pages fistly, then goes sub, sub-sub etc.. If links are same length, then shows more popular page.
You're looking in the right direction, but drawing the wrong conclusion. The 'length' of the URL, by which I assume you mean to say the depth within the site (e.g. /category/widget/reviews is 'longer', i.e. deeper, than /category/widget), is, I think, only relevant in the sense that within the site structure a sub-page will likely be linked to less often than, say, a category page. I think the navigation structure is probably of most influence on rankings of results in site: searches. Probably PageRank?
It doesn't really make sense for Google to put as much algorithmic effort into ranking results for site: searches as they do for regular searches, so I don't there's a point in trying to find a strategy there. Your internal linking structure should reflect the goals that most of your users have.