Mike Manuel offers a nice post on the uptake of wikis by PR firms. If you’re not a PRWeek subscriber (I’m not), you won’t be able to read the item Mike links to, but he does include some of the scenarios in which a wiki might have helped. A sampling:

• A press release went out with an error because the deadline was approaching and a change wasn’t implemented
• You often have projects that require the constant feedback of multiple users in different countries

There’s more in Mike’s post.