Most of the CRM systems offer at least an import/export function via CSV (Excel). The challenge is usually to build workflows and business processes which trigger live sync between the 2 systems
Now, if you look for an all in one CRM that includes most of what you need to run a small biz (including email marketing), check out our recent comparison table with 3 leading all in one CRM solutions: http://www.getapp.com/compare/integra...

I'm not sure how well it is integrated yet, but Constant Contact acquired Bantam Live, a social CRM app for small businesses, about a month ago. the press release link is below. I'd suggest calling Constant Contact to find out what the integration status is.

Source: http://www.constantcontact.com/about-...

A web based workforcetrack CRM is a quality package containing almost all of the sales process features. WorkforceTrack CRM consists of 4 basic modules, which are, sales, customer service, email marketing and web forms. Being unique integrated solution, the software allows sales managers to set targets to employees in hrms module, and plan their daily load in WorkforceTrack calendar.
The workflow is simple generate leads through its email marketing tool and web forms. And work on the leads by logging a call,scheduling a meeting/event,sending email and adding tasks. Eventually convert them into your opportunities and clients/customer to serve them within the customer service module.
Google Apps(contacts/calendar/docs) integrated and schyncronisible online. Ms Excel integration is also available for data import and exports.
The beauty of the software is you may handle your sales process at reasonably low costs.
Need more help? please contact Howard Sherwood expert in this field:+44(0)8444 842 958