delivery downtown milwaukee..tonight! help!
I don't know any particular place - sorry - but you might try going through the dining website of the Milwaukee Journal Sentinel:
You can do a search on geography (downtown Milwaukee) and even pick a type of food. You'll probably have to call places to see if they deliver, but at least that will give you some direction.
If you try something and they say they don't deliver, you could always ask if they can recommend someplace nearby that does.