Geek Boards is currently a PR5 which is quite decent. There are a lot of outbound links in the site which may be preventing it reaching the peak.

In answer to the PageRank question. PageRank is the brain child of Larry Page who inveted Google. He came up with a way of scoring websites out of 10 based on a number of factors (currently at least 250-300). A site with high PageRank (PR) is more reputable and is likely to be positioned higher under relevant searches. :)

PR10 means beast
 

Google gives importance to a website in terms of PageRank in a scale of 0 to 10 out of which PR10 means beast and PR0 is the low down position and always try to achieve a higher PageRank. In order to increase the PageRank try to get as much backlinks as possible from High PR websites and blogs.

Tips to improve the page rank

Get Incoming Links from High Quality Related Sites- connect your site with other high rated website or blogs.
Remember to use SEO techniques: - SEO plays a vital role in increasing the page rank. Implement the SEO tips to get increase in page rank faster.
Write original content.: - do not copy paste any content from one site to yours
Don’t go link crazy: - many think incoming links add credit to their website and start posting comments in forums and other discussions leaving ads to their site. This will not help in any context. Don’t do this.
Write Great Content: make sure your site content is great and unique. If you write great content people will automatically link to your site which will increase your site rank.
you can also follow some technical method like Search engine Visibility service from XnYnZ.com