Places to hide from a giant

1. In his ear. It may not be very clean, but if the giant is large enough, this makes for a quick hiding place. Just don't make the ear itchy, or else you have to dodge a scratching finger.
2. In a dollhouse. Even giant daughters enjoy playing with dolls. So long as the girls don't decide to play with the dollhouse, you could hide out in there for days without being found.
3. In the pantry. It'll give you easier access to food while you plan an escape. Other than having to hide whenever a giantess gets ready to cook, all you have to worry about is the gigantic rats.
4. Underneath the furniture. In almost any room in a giant's castle, you should be able to find a table or shelf to hide underneath. Just don't hide under a pillow.
5. A ship in a bottle. This is a risky hiding place, as the smooth glass of the bottle makes getting back out difficult. But with the proper gear and planning, it'll provide a wonderful place to hide your ill-gotten loot.
6. In the garden. Another risky hiding place, as the bugs may the same size as you. But the fresh air and fresh produce make it appealing for the outdoorsy type.
7. In a matchbox. Sometimes the best hiding places are in plan sight of the giant. Although some do question the sanity of one who would hide in an object likely to be used often by the giant.
8. In a hole in the wall. It is much safer to hide in places the giant can't easily get to. But watch out for other dangers that can fit where giants can't, like the rats.
9. In the giant's pocket. A dangerous place to hide, but can be useful if you need to travel quickly. Just don't wiggle too much, or the giant might notice you're there.
10. In his treasure room. Depending on what the giant considers to be treasure, you may find yourself with countless places to hide. Or you may just find yourself stuck in a roomful of gold coins.