Okay, enough griping. Sorry, got off topic slightly.
Then they can be crafted to speed up experience in Cooking, Fishing, Mining, Smithing, Woodcutting, and Prayer. I've only used the Fishing Urns so far, but the exp gain is very nice.
Just imagine- fish, fish, fish, kill some bait, fish, fish, fish... that gets a little boring after 90+ levels. Now, every now and then I get a notice. "Your urn is now one-quarter full"... "Your urn is now half full"... and when the urn is full, I actually get to manually initiate the teleport. Watch my little guy put the urn down, see it whisk away...
Bear in mind, I've only tried it with fishing so far, which I like very much.