I was doing some research for a project that might use GSR and wanted to post some resources that might be useful. Chris3000 has a nice page with links and info describing his own work, including a couple schematics.
Here’s a big list of links on various kinds of biopotential technology.
A Lego GSR seemed to be making its way around the tech blog world, but the original link looks to be lost to the ether. Anyway, one more link to a DIY GSR FTMedia
**UPDATE Lego GSR! with lots of other info