A few points on color management and monitor calibration

1. If you post your images on the web , print and especially sell you images you need to be sure that the others will see your colors exactly as you plan them. That's why you need to calibrate your monitor and use color management aware software.

2. Even if you can't get your hands on the hardware calibrator, you can use a free software one. It is a part of Windows 7 and Mac OSX. Win XP users can get QuickGamma. The quality of such calibration is up to your eyes. I did that before. It's pain in the butt, but better than nothing. Finally I gave up and bought Spyder2.

3. Be sure to use color-managed (CM) software. Photoshop is CM, MS Paint is not.
Use CM web browsers: Safari or Firefox >=3.5. Bad news for all-in-one Opera guys and Chrome speed junkies, they are not for photographers. Check Gary Ballard's CM tutorial, if you don't know what I'm taking about.

4. When you post your photos on the web make sure they are in sRGB and have sRGB profile embedded. That's the best we can do for our non-CM fellas to save them from seeing the saturation problems. This is the rule, by the way. The same holds for your microstock portfolio, unless the stock mentions its color space requirements explicitly.

5. Finally, if you are a proud owner of a multi-monitor setup on a Windows system, be sure you color management works fine on both monitors. Because if you don't have a separate video card per monitor, most probably it does not. Long story short, make sure you edit and proof images on you main (in windows terms) screen.