http://www.one-tab.com - save up to 95% memory in Google Chrome and reduce tab clutter. It launched on HN a couple months ago, and am currently adding multi-PC sync.
Thank you! I've been using it for almost a month, and I love it.
I currently have more than 2000 tabs in OneTab. They used to all be open and in memory. I can now watch videos without too much lag (I still have 500 open tabs that I should transfer to OneTab).