I rather dislike the term 'knowledge capture' as it implies a one-way street; knowledge disappearing into some dusty trap, never to be seen again.
The KIN Knowledge Retention and Transfer special interest group has looked at many techniques for representing knowledge and expertise.
Mindmapping and interactive Q&As can use attractive and intuitive visual techniques to make knowledge accessible and attractive. I've discovered a new variant on the mindmapping technique that is worth looking at. Have a go at the free 'concept mapping' web tool http://bubbl.us
See this video for an explanation of concept mapping (and incidentally the relationship between information and knowledge)