Not quite what you're up to, but I've been tinkering around with my pedals recently and am in the process of building a compressor. So far I've modded my Boss SD1, DS1 and GE7, and also my Crybaby. They are all sounding much better, with the GE7 in particular being much more useful and a lot quieter (it's my main boost pedal). I'm repainting the GE7 at the moment. I've been building the compressor on veroboard and just need to get it boxed up. I'll put some pictures up when it's finished.
i'm not sure how much help you'll get with the Behringer pedals, but there is a huge amount of information on modding the boss ones. There is also a layouts gallery at the top which contains lots of stripboard circuits.
If you want I can email you a word document which has a list of all the common mods I could find for the Boss DS-1, SD-1 and GE-7. They are all found in the forum above, but I put them all onto the same page.
Well, not that exactly..I may have pictures soon. There'll be some wacky sounds coming out of my sisters Furby very soon. It'll sound like it's screaming in anguish!!
*Cough*...the crazy distorted, morphed toy noises on Suspended Animation by Fantomas are an example of circuit bending, I thought there might be someone else into it.