Here are a few more theme ideas: Sundae Best (sundae-making supplies), Oh Baby (newborn), Petite Picasso (children's arts & crafts supplies), Christmas Cookie, Golf, Sewing, Night on the Town, Family Fun (family activities, games, etc.), Photography, Rub-a-Dub-Dub (child's bathtime), Hot Wheels (car care supplies), and Couch Potato (could be the same as family movie night).
Our school has never done this, but my sister's school has and they assign a theme to each class, for which the parents send items or solicit donations. I believe the PTA also solicits gift certificates from local businesses such as restaurants and video stores.
Last year was the first year we did theme baskets for our auction. The person who organized it had fun names for each theme. Some that she used (minus the neat names) were; Everything Barbie; Baker's Delight; Geared for Dad; & one for Moms. The rest that I can think of were similar to ones already listed.