In the latest version of Office Live we introduced a new feature called Data Sharing. Essentially this acts as a pipeline between your public web site and web pages and your private site Business Applications on Office Live. You can use Data Sharing to either pipe data into a Bizapp list from a form on your public site or, in reverse, you can use it to pipe data from a Bizapp list back out to your web site.
I created a little screencast demo on how to create a form to collect leads from your website and integrate it into your Business Contact Manager bizapp. It's pretty cool, if a little geeky, a feature only a developer could love.
Anyway, here's the link to the video. Check it out.