It's boring, but toddlers love hummus. So for them, plenty of raw veggies (esp red peppers) and crackers to dip makes for a happy little crowd. That plus grapes and clementines and your minis are thrilled.

Inarizushi are little sushi-rice pockets. The wrappers are abura age--fried tofu. They are really delicious and both kids and adults like them.

Endive leaves make great spoons for all sorts of things- I mix cream cheese, blue cheese, apple jelly, pecans, and cranberries and serve them in endive "spoons." Maybe leave out the blue cheese to make it more child friendly.
You can make socca (little pancakes with garbanzo bean flour and olive oil) and serve them warm and plain or dusted with some Parmesan.
I think pickles, olives, and pickled veggies would also work well. I watched in amusement at Thanksgiving as my friend's 2 year old devoured olives and dill pickles and completely ignored the desserts.

Mini grilled cheese sandwiches (just make regular ones & cut them into small squares or triangles)

Mini mac & cheese: there's a great recipe from Food & Wine mag. that uses a muffin pan for individual macs & cheese

Both of these could be made ahead & then just put on a cookie sheet & kept warm in a low oven

In my experience kids like anything they can pick up and eat easily so things like dip platters with carrot, celery and red pepper sticks and cheese cubes are a must. Likewise, platters of fresh cut fruit in lots of colors will appease both young and old.

You could also try vegetarian spring rolls which can be made a few hours in advance and then covered with a damp tea towel to keep this fresh. Or you can cut all your filling ingredients up ahead of time and then assemble them just before your guests arrive.

Savory pastry pin wheels are easy to make and can be made in advance and refrigerated (or even frozen) until time to serve. Just spread sheets of store bought puff pastry with tomato paste/pesto/olive paste top with vegetables of your choice (capsicum and mushrooms work well) and grated cheese. Roll up and cut into 2cm think slices, place on a baking tray and cook in a moderate-hot over until golden brown and puffy. You can make vegetarian pizzas in a similar way by cutting small circles out of the pastry and topping them with vegetables and cheese (for a more adult version try caramelized onion and goat cheese)

Also mini quiches, sushi, exciting finger sandwiches (think sliced roasted vegetable and pesto), tomato, bocconcini and basil on toothpicks and vegetarian arancini are all other good choices that can either be made ahead of time and served cold and can be easily adapted for both children and adults.

The finger food collection from www.taste.com.au is full of inspiration too.

Have an amazing party! Good Luck :)

Blisstree has a fun list of vegetarian appetizers, including goat cheese lollipops (well, cheese balls with sticks -- use tofu cheese for vegan.)
http://blisstree.com/eat/vegetarian-appetizer-recipes-holiday-cocktail-party-874/

My mother makes a vegetarian ceviche. She uses jicama and heart of palm instead of fish

My go-to appetizer is a huge hit everywhere I take it - I've gotten a few marriage proposals out of it! :) Recently my 2-year old nephew tried one and LOVED it.

Caramelized Onion, Chevre & Fig Jam Tarts:
- I use 1 package (4oz?) of chevre and 1 package of store-bought pie crust for this.
-Caramelize 2-3 onions
-Using homemade or store-bought pie crust, cut into small circles (fit to whatever muffin pan you're using) - I then re-roll the scraps to get more circles; pre-bake in pre-greased pan @ 375 for ~10 minutes
-Layer each tart with some onions, chevre, and then a dollop of store-bought fig jam
-Bake for another ~10 minutes (You want the jam on top to be just a little crispy

Sorry the directions are so lackadaisical, but that's kind of how I cook. :) I serve these warm, or cold, or room-temp. All delicious. So easy, but everyone thinks you're a gourmet cook. :)

I make mushrooms stuffed with a thick, seasoned white bean puree topped with some parmesan cheese. nom nom

@kittensandpie: that sounds delish! i just saved the recipe for my christmas eve dinner party!

Cut pita into 1/8's. Toss in olive oil and s&p and cumin and garlic powder. Bake off at 375 till crisped.

Throw a head of garlic in some foil with a bay leaf and olive oil and s&p with the chips.

Let the garlic cool and then squeeze into a food processor with a block of tofu and ahandful of basil leaves, s&p to taste and the juice of 1/2 lemon. Puree to smooth.

Garnish it and serve with the pita chips.

I've served this on catering gigs and people are sometimes amazed it's tofu.