New way to advertise Mozilla products: print their logo on stamps?

While talking with gerv and justdave on IRC about the Committer’s agreement and asking whether MoCo was paying the stamp back, I suddently got a (bright?) idea: why not advertise Firefox, Thunderbird, Calendar, etc… by printing their logo on stamps? The only problem is that you cannot create your own stamps as you want. But this would be a cool way to bring Firefox & co. in all houses.

PS: if a chief of some post offices is reading this blog and you had no idea what to print in your next set of stamps, now you have one.