(text mostly from a post from La Monte Henry Piggy Yaroll)

experiences using conductive conductive clays, adhesives, and inks

It works well, but there are a few caveats.

Generally, these compounds don't conduct as well as solder or plain copper. Many nickle-based compounds have resistances in the ohms per mm range.

Furthermore it can take a few days for some of these compounds to reach their final electrical characteristics.

hint: Silver-based compounds are more expensive but their lower resistance makes things MUCH easier. Take measurements .

I've also had some unexpected problems with the solvents attacking plastic components in my devices. Test your inks and adhesives with ALL the materials you will be usingin your device.

Andrew. also found an interested related article: http://www.mst.dk/udgiv/publications/2000/87-7944-187-4/html/helepubl_eng.htm ...in short, handle with care and in a well-ventilated environment.