I've done carrots and squash with yogurt with rousing success; they're on the sweet side and go well with either a bit of cinnamon or maybe some cumin. I've also done broccoli and spinach in yogurt, although with Josie they went better with cottage cheese.
You could also puree some cucumber and make cucumber yogurt sauce, like the stuff that goes on gyros. Especially yummy in hot weather!
I've also mixed yogurt and guacamole together, and that has the added benefit of staying on a spoon pretty well when Natalie wants to try feeding herself (or she wants to try decorating the kitchen with her food LOL).
Yogurt can also be used as a dip for fruits or veggies. You can mix it with anything you'd put in a dip, like seasonings for Ranch dressing. You might find you like yogurt if you'd flavor it differently. Lots of cultures use it in ways other than sweetened and/or with fruit! Oh, and it makes a good marinade for meat, helps to tenderize it.
One of our favorites here, although it's not an actual food in the same sense, is to mix Nordic Naturals fish oil - orange flavor is yummiest, although their peach is nice too - into yogurt and sweeten slightly with a couple drops of stevia (natural sweetener, ZERO glycemic index
- available at Whole Foods in liquid or powder and Trader Joe's in powder; we prefer liquid here). Add a bit of vanilla and you have a tasty treat for dessert, breakfast, or snack - tastes kind of like orange creamsicle!