I've blogged some time back about using blogs internally within our company.  We've used these blogs internally to capture info, describe problems/fixes and share articles. 

Since we've been using the Intersoft WebGrid.NET component, I've created a light wrapper around the control to provide common functionality used across pages in our asp.net application.  I've been using the internal blog to discuss how individual features we require can be implemented.  Others can check out the code and add comments to it as we go.  This provides a nice way to capture the information we need and document feature implementations along the way. 

While a wiki may be more appropriate, I'm much happier with the blog engine for now.