Adding email address from Gmail to Contacts Suppose I have a contact in Contacts named John Smith. John's email address is jsmith@gmail.com. I've emailed him in the past, but I've never  added his email to his contact details. Now, suppose I compose an email to John, then as soon as I type js, Gmail guesses that I want to email John and his full email address pops up for me. At this point, I'd like to copy his email address and add it to his contact details in Contacts.

Any way for me to do that easily?

I'm using ICS on the galaxy nexus.
You don't need to copy the email address. Gmail pulls it from an auto-created contact (with only one value). Merge this contact with the contact you created manually.

Procedure: Using stock contacts app, Select the contact in which you want to insert email. Tap Edit from menu. On Edit contact screen, tap Join from menu and choose email address contact.