You mean tool for competition backlink analysis, so it show you URLs where your competitior have backlink and also show its Pagerank?
This is what i have in mind:
1. Use Mozilla Firefox and install SEO Quake addon, at google, search for link:yourcompetitor.com and it will show the result pages details including pagerank
2. Use http://opensiteexplorer.com
. Select inbound links tab and Highest ranked backlink pages has highest authority
3. Use LinkAssistant
SEO Spyglass (very good on competitor backlink and more analysis!)
4. Use other online tool, search for something like competition backlink pagerank analysis)