The online accounts we should sign up

The world is evolving. Internet already becomes a need for everyone just like electricity and mobile phone service. There are a lot of freeware, open source applications, online services, even free OSes. Internet connects everyone of us with our friends despise the geographical differences.

So, what online accounts we should sign up? Popularity is the most essential factor. And also based on your area. Because some services are popular in one country but not the others. The list below is only based on my opinion:

Email account - GMail, Yahoo! Mail, Windows Live Hotmail. Sign up these webmail services not only allows us to use email service, but also other services depend on the corporation provides. For example, Windows Live also provides Skydrive service for us to upload and share our files. Google provides Picasa Web Albums for us to share the photos.
The most prominent email service is GMail, which provides IMAP and POP3. And IMAP is integrated with Mozilla Thunderbird. Great!

Social networking service - Facebook, Twitter. Connect you with your friends. They are very very popular.

Blogging - Blogger, WordPress.

Photo sharing - Flickr.

Other services:
Xmarks - Synchronise our bookmarks.