Blogs and wikis might not look different from the first look, because they both enable groups of people or individuals to share information. On a blog, only author can edit or delete any information he or she desires. Other individuals can only contribute comments with text and links on a blog. Blogs are good for announcements and news but not so much for creating and maintaining documents.
Wiki is an excellent tool for a collaborative work because document can be edited, updated and expanded by anyone with access to it. According to Wikipedia on Wikis, “Wikis may exist to serve a specific purpose, and in such cases, users use their editorial rights to remove material that is considered "off topic." Such is the case of the collaborative encyclopedia Wikipedia.[2] In contrast, open purpose wikis accept content without firm rules as to how the content should be organized.”
Blogs can also be used in brainstorming and generating discussion. People can leave feedbacks on a blog post, which can lead to discussion or collaboration.
I think a new use for a wiki would be to keep family emergency information but in a “private space”. Family members could write, update and change information.