Yahoo Webmaster Tools are better than Google's - I've found Google's webmaster tools to be disappointing. Most of their monitoring tools are infrequently updated and their backlink tool is completely useless (it shows a very small percentage of actual backlinks). Yahoo's new Site Explorer on the other hand, it frequently updated and the backlink tool is great. The only downside is you cannot tell which backlinks are follow or nofollow. Otherwise, Yahoo's built a winner.