Many sites I come across use a ball internal linking structure which leads to each page getting an even share of internal PR:
When conducting SEO for sites that have multiple main areas of business, I try and build a multi-pyramid internal linking structure. This distributes the PR as I wish, and gives a level of control as to which of my pages appears in the SERPs.
Here is the linking structure I use in this instance:
If I wish to give the home page a boost, then I give each page a tunnel home as in the diagram below:
This strategy has really worked for me. Further details on dynamic linking.
Comments, suggestions for improvement are most welcome.