Google scholar now has all US District court cases, all 9th cir decisions, and all SCOTUS decisions. It also has most state courts of appeals and supreme court decisions. Since legal research 101 is (a) look up the statute, then (b) look up cases referring to that statute, and you're providing (a), it would be nice to have (b) just one click away. In a sidebar maybe?

Or even zero clicks away- just pre-load the Scholar search via google's API. It probably wouldn't even slow your page load time.

Default options should be "Oregon and Federal Cases, Anytime"