The pulse is a mini-blog that is displayed on the site and is usually a one or two sentence blog about what's going on at the time. The pulse can also be sent out to your friends' cell phones.
You can also nudge other people, build up or purchase credits, and use credits to give people a "mini" (miniature picture).
Because it combines social networking features with blogging, Xanga is a great choice for those that want to start a web log and actively participate in a community of bloggers. It will give you a chance to meet new people which, in turn, can lead to more people reading your blog.
For those more concerned with the blog-side than the community-side, a more traditional hosting site like Blogger or LiveJournal might be a better place to start. Because they concentrate mainly on blogging, they have a fuller feature set. Thus, it becomes easier to customize a blog with templates, widgets, and link lists.