Many local vet's will put up flyers, so check with not only your regular vet, but others in the area. If your vet has a large cage they can put in the waiting room they may let you put them there for a few days. Petco has pet adoption days, check and see if you can bring the kittens. Also check with some rescue groups in the area, they may be able to list the kittens on their websites as courtesy listings. I would recommend unless you know the person charging at least a small fee for the kittens, that helps cut back on people who do not truly want the kittens for a pet. Once you meet the person you can always decide not to charge. You did a really nice thing for momma cat and her kittens, good luck on finding the kittens wonderful loving homes!