Shipping my bike across US (DC > LA)? OK!

So, I have my (large) single speed in the DC area -- but have just relocated to the LA area. I'm wondering; What is the best and most economical way to have my bicycle shipped across the states?

I'm hopping for an option that is $100 or preferably less.
This question may be what you are looking for: How to get a bike from one city to another in the U.S

Besides the obvious UPS, USPS, and FedEx, there is train shipping as Daniel suggests. Some bike shops and outdoors stores will pack and ship for you (good if you are not mechanically inclined). Bike shops are a good place to get free bike-sized cardboard boxes for some odd reason...