What's the oldest satellite still orbiting earth?

According to Wikipedia, it is Vanguard 1, which has been up there for almost 50 years and is expected to stay up almost another 200 years. Since it's batteries died over 40 years ago, it's little more than a chunk of metal now.

Right. Discover Mag (5/06) had an article on over 1,600 satellites, including Vanguard 1 which proved that earth is not perfectly spherical, and including Cute-1, less than 4 cu.in. in size, that was built by university and high school kids in Tokyo, and sends information that it's still working - and that is all.