How do I connect our Google Apps email & contact data with a powerful CRM? And what's API got to do with it?

Our small team has a Google Apps deal set up w/ gmail, chat, docs %26amp; spreadsheets, etc. But we would like to integrate this into a more robust sales contact manager or CRM like BigContacts (www.bigcontacts.com) or Highrise (www.highrisehq.com). Or something similar/better/less expensive. Anyone? Thanks in advance!|||The only cost effective way is to use an online CRM application that has a bi-directional web services api such as Salesboom.com