Ideas for using garlic scapes (other than in pesto)?
Personally, I just throw them into stir fries or fried rice (add them near the end of the cooking time). I've also had them slightly stir fried with pea shoots in sesame oil. Simple but delicious.

Tofu666, an amazing vegan blogger, fries them often. Here's a sample:
http://veganmenu.blogspot.com/2007/06/seitan-and-lentil-stew-fritto-misto.html

This page has instructions for pickling them:
http://notwithoutsalt.com/2009/06/18/garlic-scapes/