Finally, MC has a speedy transportation solution. Unfortunately, that solution involves falling out of the world and becoming permanently stuck in a bridge.
SO!
I built a railroad. (Or part of a railroad).
The railroad only goes to near Aaronjer's big bridge because terrain won't load while you're riding a cart, so going much further would dump you into unloaded terrain (which is bad).
Also, remember, always ride the car in the right lane (this is a US server after all). There are some track sections that shunt you onto the correct track if you're on the wrong side, but still...
Also, don't mess with the carts in the tiny short sections of track that run parallel to the main track. These are boosters, and need to be in their 'reset' position in order to boost the next car that comes through. Everything should wind up in the correct state automatically as you use the track.
Here's how to ride the track!
First, from the spawn, notice the huge flight of stairs with the sign indicating the trainstation. Go up these stairs to find a train station.
http://superjer.com/nezumi/mc_railtutorial_1.png
Down below the train station, you'll find the spare cart queueueueueue*.
http://superjer.com/nezumi/mc_railtutorial_2.png
Redstone torches change the direction of track curve sections under some circumstances. What you'll need to do first is take the redstone torch provided (Or your own if there isn't one around) and put it where it is in this screenshot:
http://superjer.com/nezumi/mc_railtutorial_3.png
Then go down below, and push a cart up the hill to the loading zone. Next, put the redstone torch where it is in the final screenshot.
http://superjer.com/nezumi/mc_railtutorial_4.png
Finally, push the cart up to the block marked with a star, and get in. Hopefully, the cart should roll off the far side of the block, and be off.
TO RETURN:
Just push the cart down the hill, and jump in. You should wind up back at the station near the spawn, in the spare-cart queueueue.
Enjoy!
* If anyone knows how to stop spelling queueueueueueueueue please let me know.