301 and pointing to folders in a site

I am having to merge a number of seperate sites into one site. I plan to use 301's on their old urls, to point to a subfolder, and not the index page of the main site. i.e.
www.blue-widgets.com is now going to have a 301 pointing to www.widgets.com/blue.

I wonder if google will transfer the PR through to that subfolder. And also whether it will think this is spam or not.

any comments anyone? please?!