Ability to link emails to contacts and companies

I like the ability to link an email to a deal.

Can we have the same functionality to link to a contact (person) and a company?

If the email is sent directly to / from a contact then it is captured, but not if it is forwarded on (eg an email could be received or sent that contained DB info on a person or company - it would be great to be able to attach this to contact / company).

Thanks