How to find my competition's backlinks?

Is there a program or preferably a free way to check into my competition's backlinks? I don't mean to see how many backlinks a page/site has because I can do that with Traffic Travis, but to see WHERE those backlinks are coming from?

I think I found another 2 niches today, and the competition is not optimized for the keywords. However, what strikes me as odd is that for one niche the first two results are pages that have a PR4 but the first result isn't even a year old. They do have ~1000 and ~1900 backlinks pointing to them respectively though.

So it got me thinking "wow, what kinds of backlinks is this site using to obtain a PR4 so fast!?"

The rest of the results show the third position with a PR0 deep page from a PR5 site. This particular page has NO backlinks. None of the top 20 results are optimized with inurl, allinurl, intitle, etc.

Is this a niche that you guys would still go for or is it yet one of those newbie mistakes where I'm thinking I've found silver but it's a more like copper?

Edit: forgot to mention that the exact match .org is available for me to purchase.