Wait until they are old enough to attack your stash or threads! I'd love to have another kitty or 2, but we're maxed out...not enough space as it is...
my dreams some day would to have a feline santuary (sp) where people can bring abandoned cats and just leave em, no worries...they are adoptable if desired, but I'd house them and take care of them throughout their lives...unlike most shelters which euthinize after a certain amount of time.