Perhaps Coffeeweed, Sesbania herbacea Here is a link that might be useful:

Thanks. And sorry for the double posting; not having been here before and with so many forums, I couldn't tell where the traffic was. Looks like it's everywhere. Check tree forums, anyone, if you're curious.

I think this is the Mediterranean Slant-faced Grasshopper (Acrida ungarica).

Thanks! I guess maybe I should pull it out then, as Gleditsia triacanthos seems to have an entry in the UC Davis invasive species list. cal-ipc.org also talks about it being potentially invasive.