I picked up one of these last night,
http://www.seeedstudio.com/depot/dso-nano-v3-p-1358.html?cPath=174 (http://www.seeedstudio.com/depot/dso-nano-v3-p-1358.html?cPath=174)
It's a tiny little thing. It does work well for effects type circuits. I mainly got it so it would be easy to look at LFO's and other CV circuits. It's great for doing this. It's also got a little square wave generator in it -- it looks to be pretty useful for debugging builds too.
Oooooh. Want.
I have the older, lesser, panelized model, and I'm quite impressed with it. I do wish it would measure frequency at audio levels, but otherwise it's more useful that I'd hoped. The Nano V3 looks ever awesomer.