The Human Clock is a fine piece of Internet art. Israel Sela, who should get himself a LiveJournal, brought it to my attention.
A more serious resource, the 10,000 Year Clock is very aeshetically pleasing, if not quite useful at home. It is one of the ideas fostered by an interesting organization called The Long Now Foundation, folks dedicated to really long-term thought and preservation. Their library project's credo is worth reading, and something concrete that's already in the works is The Rosetta Project, co-produced with The Lazy Eight Foundation.
I like this lazy, long-term thinking in this breathless age.