I printed this blank heart mat from a site I just discovered (and love) called Prekinders. Note: I am adding it to my resource list. I then added some letters that S is familiar with to create a "letter search". We used a different color of dot marker to mark each letter. I modeled this for him to begin (some of the S's) and then had him point to the letters before he marked them himself. As you can see, his attention span did not last for the entire activity, so next time I will cut the mat in half.
Thanks, Activity Mom, for the site!