A good, decent PR (Page Rank) is a PR4/PR5. Once there, you can count on Google spidering your site consitently. It's only a Google thing though, and has no bearing on Yahoo!, MSN, etc. results.
In essence, it's Google's opinion of your site based on incoming links. It's extremely easy to manipulate, and that's why you see so much SPAM in Google's SERPS. The smart ones, like OWG, use this flawed system to their advantage, getting free traffic to their sites, as well as providing a service to their clients.
To find your site/page's PR, don't IMHO, don't waste your time with their silly toolbar. Just go here:
http://www.freeweb-hosting.com/googl...nk_pr_checker/