Originally Posted by drewdlephone 
ColorVision Spyder 2. Made one hell of a difference on my MacBook. I can take my shots off my computer to work and get prints made, and as long as they don't touch it with the auto-corrector, it's identical to the colors on screen. Best hundred dollars you can spend, in my opinion, especially if you intend to show your work online or have prints made at a lab.
There should be (is no) no auto corrector when printing digital files. If your files are coming out of a calibrated workflow and are tagged with the correct colourspace for the lab (sRGB is generally considered the appropriate one), the lab should be able to print it with no imput from the operator, and give you back very close to what you saw on your screen.
This presumes the lab is also running a calibrated workflow.
I take files from my computer to work on a regular basis and am almost always able to print with either no corrections or very minimal corrections with our in house lab. Small corrections are inevitable because even two well calibrated systems will not be running absolutely identical.