Well, that small JPEG on your blog may only have a few pixels, but it took a mega-pixel CCD to shoot the uncompressed original. BTW, hang on to that uncompressed file, for later editing and to prove that it was your photo there on the blog! Also, your photo may one day become famous. To print it at the quality common in magazines, or to to view it on high resolution screens, you'll definitely need a megapixel image. The resolution of printers increases all the time, while there will be plenty of screens in future with much higher resolution than what is common today.
So, yes, we all love more megapixels. But I like to add another argument for higher resolution. I call this happy snapping. We all want it and megapixel CCDs make it a lot easier. Let me explain.
What you want is a photo that captures that smile on the face of your children. You want to capture that moment when they open the box with their birthday present. You want to capture all the surprise, joy and delight that makes their eyes light up, without the eyes turning red because of flash. When people have to pose for pictures, you won't capture that spontaneous magic moment that makes that one photo stand out. By the time you have set up your tripod, that moment is lost. What you want is happy snapping!
For happy snapping, the camera must be virtually invisible. Looking through a viewfinder makes you into an intruder, instead of someone who participates to make it happen. By actively contributing, you also get a better feel for what is the right moment. Shoot straight from the hip, before you lose the magic of the moment. If you can, shoot a whole sequence of photos, without flash, as rapidly as your camera allows, in the hope of getting that one magic moment right.
Note also that, for this kind of photography, it's best to use a wide-angle lens. That way, there's a better chance that people will show up on the pictures without their head cut off, or without other essential parts of the picture missing. It doesn't matter if most of the pictures are useless, as long as you did catch that one magic moment. It doesn't matter if you need to crop away more than half of the image. If most of what's on the picture turns out to be a pillar that was partly in the way, then that doesn't matter; just cut it out, as long as you did capture that smile somewhere on the image.
So, you may well end up using only one-tenth of the original picture. But it's that small part that makes it all worthwhile. Nobody need ever see that huge pillar that took up more than half the original picture. But if you enlarge one-tenth of a picture, you'll need a high resolution original to avoid pixilation.
Finally, you may be concerned that, especially without tripod, you'll end up with fuzzy pictures. That's why many cameras nowadays have intelligence to compensates for hand-movements at the moment the picture was taken. If you shoot a picture with shaky hands, the object will effectively move over a larger frame, thus effectively further increasing the number of pixels you need for the photo.
So, I'd say, go for those extra megapixels, and go happy snapping!
For more details:
http://www.samsung.com/PressCenter/PressRelease/PressRelease.asp?seq=20060309_0000239138#