I see some of my competitors have better pr than me and i assume that they have better and more inbound links than me. I search for competitors name on google and see who links to them. However, I assume that there must be a better way to find their inbound links than google's backlinks option.
Once you get into the more advanced levels of link building, you'll likely want a tool that can provide more info, such as the anchor text found in those links, the IP address those links are coming from, the PageRank of those linking pages, etc.
For that, you'll need a tool like OptiLink, SEO Elite, or Backlink Analyzer.