I set up a super-simple scavenger hunt for Jack this weekend to introduce him to the concept. I made a list of three things for him to find in the backyard and told him to check them off as he collected them. (He's familiar with the list concept -- we're BIG list-makers). We attached a little pencil to his clipboard with string and tape and off he went. He loved the whole adventure. And the simple act of scribbling in the box (or making a check mark, or an "X" if your child's up to that) is a great pre-writing activity. I think this will be the first of many scavenger hunts for us.
I tried a similar idea with an older (kindergarten) child that I work/play with yesterday. On his list I made some letters of the alphabet and he had to hunt for objects in his playroom that began with each letter. He also loved hunting about.
There's something about clipboards that children find so grown-up and appealing. Have you noticed? (I have to admit I have a thing for clipboards myself!) I hung a clipboard on the shelf alongside my son's desk using a little cup hook, so it is at the ready when inspiration strikes.