One of our favorite solutions for a small space is a low stacking stool. If you need to pull out extra seating for a party, they work really well. Plus, these little guys actually look good hanging out in a corner stacked one on top of the other...
A few that we like:
• Tribo Stool (shown above) from Design Within Reach, $215
• Artek Alvar Aalto Stools from Finn Style, starting at $210
• IKEA's Frosta Stool (a knock-off of the Aalto), $12.99
• IKEA's Benjamin Stool, $19.99
• Vitra Elephant Stool, $135 at Design Public