i'm appliqueing mine to fabric strips- in different (layouts) the (plan) is to then cut the strips up, frame them with black- stitch together into a quilt---so far i am loving it! and the stitching them down part? when i mentioned to hubby my intent-he said what you said- would probably take forever-it's not so bad- they actually go together quite quickly (i'm stitching around each one with an invisible stitch.
i've seen them attached with just a button in the middle too-
and the little dolls/animals/clowns made out of them are very very cute.