Peas will produce well in the cooler fall weather, and will stand some frost. Getting them to sprout might be a trick (same problem you'd have with carrots and lettuce- the soil may be too warm for the seeds to sprout)

IT's a LITTLE late, but you could plant some onion seeds, for sets for next spring. Plant them in a block or wide row, sown heavily... don't thin much. You want them crowded. They'll start bulbing quickly because the day length affects that, and you should get hundreds of dime size (the perfect size set) sets to plant.

Here is a chart that shows germination percentages in various SOIL temps. This is where a soil thermometer is VERY useful.
http://tomclothier.hort.net/page11.html

Summerthyme