actually, the water itself holds very little bacteria...it's the surfaces in the tank and filter that hold bacteria. using a cup of gravel from an existing tank, rocks, decorations, plants...this all helps. also if you happen to have bio wheels you could take a used one and put it on the new tank - or aquaclear filters, you can run 2 sponges in the filter, then pull one and put it in the new tank.
its still not an instant full cycle...but it does give you some bacteria to start with, which means you could add a small fish load after a couple days...then slowly stock the tank with a few fish each week (really depends on the tank size, type of fish, etc...but you get the idea)