Every now and then I check the directory listings I have at Yahoo! to see what is up with them. I have bookmarked them ages ago and when I have some free time I check them out. I checked last night and noticed that Yahoo! has added the "Save to My Web" button to the top right corner of the pages.
Social search, online bookmarking, is found everywhere with Yahoo!. In Yahoo! Local, where I bookmark phone numbers I use every now and then and now in the directory, which gets less and less attention from Yahoo.
The little 
icon to me is very useful. If you want to see my listings you can check them out in the New York Consulting list or the generic Yahoo! Web Rank.
I posted a forum thread on if this is a new feature for the Yahoo! Directory or not at Search Engine Watch Forums.
