If you are writing content to increase your pagerank and hopefully your ranking then it becomes important to know the minimum page length that you can get away with posting on a regular basis without getting you penalised by Google. Although Google doesn’t have a minimum length that they recommend that doesn’t mean that really short pages are indexed and even if they are it doesn’t mean that short pages are treated the same in terms of generating and passing on pagerank.
Google does refer to a manual penalisation for something they call “thin content”. This doesn’t actually refer to the amount of content but the quality of it. For instance if content looks like is has been automatically generated or it isn’t unique. So the content needs to be long enough to be unique.
The most likely answer is if there is enough unique wording on a page for it to be indexed by google (90 words is enough) then chances are it will generate and pass on pagerank to your site and / or sites the content links to. However large numbers of pages on a site that are this short may be taking a risk. You will probably get away with a lot less than the 300 – 500 words most people recommend. You could probably half 500 word articles and publish them in two halves to get twice as much PR juice.
Some pages have a very large “template” as in a lot of text that is repeated across many pages on the site. This includes a lot of links in the navigation, maybe pages with the same text in sidebars and text in the footer. If your pages have a very cluttered template containing a lot of text then you probably need even more unique content in the centre for it to be considered a truly unique page.