This was shared on Twitter last night and I thought should pass it on here.
Social Marker
It's very simply to use, just drag the icon to your browser toolbar. When you read something you feel needs to be bookmarked, perhaps a client's blog post, select text you want to highlight and click the icon. A form will be populated and then just add tags. You can submit to all 49 sites or a select number.
There's also a button to add to your blog and website