What are some good stationary appetizers for a reception?

After contacting a caterer and learning that it would cost about $4000 for a few stationary appetizers for only 100 people, I've decided to try providing them myself. So, I'm looking for ideas for appetizers that can either be easily prepared in advance or put on a platter/in a bowl right before the party starts. Things similar to a cheese & fruit platter or a hummus platter - nice, doesn't need to be heated up or cooked, can be left at room temperature for a few hours. Any ideas?