Here is a what happens when art and electronics mix. This is LED covered wall is activated when a drop of water covers a small contact patch surrounding the specific LED. The basic principle is so simple yet the art created looks great. You can read more about this built on the link provided.
Basically there are two exposed pieces of metal around each LED (that correspond to each LED)… All said and done, taking some measurements you generally wont get much lower than 100k, but it is geometry dependent. However, for many LEDs, especially super efficient super bright ones, this is enough current to get a pretty bright light coming out of them (we attempted with a small pad 1206 pad on a PCB we had around and a super bright 3mm blue LED).