I'm not sure whether I have posted one of these before, but at about 3mm long, it hangs around the St Andrew's Cross spider webs, picking up crumbs from the larger table. It's called the Dew Drop spider, and was taken with my 300D, and the 100mm macro lens about 18 months ago.
To me, it looks as if it is either silver plated, or has a bit of aluminium foil wrapped around its body. That's what initially made me notice it, I thought it was a bit of foil caught in a web.