it's pretty easy to achieve a pr 4 or even 5 without doing too much. i have a site that all i did was add content, and maybe get 10 crappy back links, which now has a pr 4. it doesn't mean anything anyways.
I think PR3 is almost a given if you have a little half-decent content and no ads and you're around long enough to get out of the 'sandbox' or what ever you want to call it. I recently checked on two domains on a hosting account that will be expiring soon where I had intended to start e-commerce sites. They were going to be a partnership with a local business but it fell through. I had put up a few blog entries and 'coming soon' type pages as filler while I was setting up OS-Commerce. They were both PR3 even though I had done virtually nothing beyond the initial start-up almost two years ago.
Make an Ebook on how you made a pr 3 site in your sleep sell it on warrior forum then turn it into a link directory and sell links on sitepoint. I would say you are set 4life. Retire and drink mai tai's by the pool. Lucky bastard.