I have been looking for a memcache client that plays well with gevent, and I stumbled upon one today:
It’s written and maintained by the good folks at ESN.me. They built Battlelog, the social network for Battlefield 3, using gevent and this memcache client. They also released a gevent-compatible MySQL driver and a few other interesting python projects.
I’ll be doing load/stress testing with various different clients and setups for flask/gevent in the coming weeks, and I’ll post my findings here.