Here's an oldie but a goodie: balloon animals. DS is currently having a blast with them. A book and/or list of web resources, assortment of balloons, and a cheap pump or two would make a fine present for a kid who's never tried the activity.
The two main balloon types are 260 (2" filled diameter) and 160 (1"). The two biggest makers seem to be Bellatex and Qualatex, the latter of which we use; avoid no-name brands which may make ballons that pop easily, and aren't as easy to work with. The 1" balloons might be better for very small hands.
