PCB design without having to do schematic first?

westfw:
You can do it in EAGLE. Just start up the board editor and place "packages" rather than devices, connect pads with the "signal" wire (or not, I guess) and lay down tracks.

It's a really bad idea, IMO. There is tremendous value to the redundant error checking you get by having the tools check both the schematic AND the board, AND making sure they agree.

Thanks. I'll try that in Eagle.

What kind of error checking could I get for a qfn-32 breakout board?

I want to make one with 0.5" spacing and ICSP header, and maybe a pad for a 1uF cap.