I'm a big fan of all the wee things that come out of Leafcutter Designs (previously). Now, for Valentine's Day, they've got tiny packages of TCHO chocolate in their shop. If you order 12 or more of them, you'll also get a 005 Micron pen so you can decorate the little bundles of chocolate-filled joy.
Of course, if you want to mail these out, you'll have to put them in a larger mailer first.