You could try the paid version of the InfoGeniuz WP plugin for Contact Form 7.
I’m just starting out with it myself, but my initial tests seem very promising. They also have versions for CForms II and Gravity Forms, integrations with Aweber and SalesNexus, and more coming.
Just make sure to back up your WP in general, and contact form settings in particular, before activating. I think there’s a bug in this version that reset the content of my Contact Form 7 e-mails to their default settings at install, and it took me all of four minutes to write the e-mail again. 😉 That’s a small price to pay for what this plugin provides, though. And it will probably fixed quickly, anayway.