My eMac account has many features. My favorite thing about it is that you can customize however you like. My second favorite thing would be that I can take pictures on Photo Booth and use them as my profile picture. Last but not least my third favorite thing is that since it is Apple, it is much easier to manage.
iGoogle is a little but very versatile space online. You can look and see news, games, virtual pets, and just little online knickknacks. It is part of a Google Account. My Google account is i.luv.summer.of.69.
Slideshare is a place where you can upload and share PowerPoint presentations. My username is guangzhou1999. I think it is cool how you can share a PowerPoint (and Keynotes exported as a PowerPoint). Another cool thing is you can upload it onto your blog, which is even more convenient.