If you're a diehard Yahoo fan consider their upgraded widgets. They bring updates and live info to you in a compact package and work for PCs and Macs. You can keep them arranged in a widget dock and new additions include a gallery widget, which allows you to browse the widget gallery without opening your web browser.
While Yahoo Widgets work for both Mac and PCs, they are especially great for PC users, who in my experience don't traditionally have as many widget options. The handy notepad widget is much like the igoogle stickies add-on, and the weather widget will keep you in the know all day. There is also a great selection of user-submitted widgets, a la the selections Apple shares. My personal favorite is their new flickr widget that lets you upload, tag and display your flickr photos.
Download Yahoo Widgets and test them out for yourself.