PageRank?

I found - and forgot to bookmark - a PageRank calculator yesterday, and was making some - I thought - intriguing comparisons. This site has a page rank of 5, which I guess is OK, but the funny thing is this is better than a few of my company's sites. Now, I know I haven't had time to get any SEO work done, but I think it's about time I wrote a strategy paper for this. On the laziness front, the other baseline indicators I ran were quite intriguing. Lou Rosenfeld, for instance - who was complaining about my laziness in getting an RSS feed up the other day, that was my butt kicked - has a PageRank of 6. Anyway, while doing this baseline comparison, I realised I had no idea really what a decent baseline is. While I understand the theroretical idea behind the PageRank algorithm, I'm now realising that I have no idea what the end figure means. Can somebody fill me in as I'm feeling a bit stupid?