WARNING: This is for amateurs who are looking to get into macro work. For those of you experienced, you may not want to waste your time!

Over my time on dA, I've had a handful of folks ask me what kind of equipment I use to shoot my macros. Some are just curious. Others look to see what equipment I use and wonder how I get the shots I get.
(Disclaimer: I an NOT holding up my work as great. There are others on dA who are true masters at macro. This is to merely show you what you can do without sinking major dollars...beyond your regular equipment, of course!)

I shoot with a Nikon D100 (though I am seriously lusting for a D300!) and either Sigma or Tokina lenses. As a serious amateur, these lenses suit me just fine.
None of my lenses are true macros, nor do they have macro switches or settings.
But I've found an inexpensive alternative to the more expensive lenses. I use an extension tube that sits between the camera and the lens. It has no glass. The shots are pretty doggone crisp and this relatively inexpensive alternative yields suitable results...at least for me.

Now...a cautionary note or two: If/when you begin searching for an extension tube (or you can buy a set of various lengths that will yield varying results, i.e. macro magnification), do yourself a favor and make sure the tube is compatible with your camera. I'm not just talking about campatible with the make and model, either. Make sure it meters and auto focuses with your camera. You can find some real cheapies out there that have little functionality. But do yourself a favor -- you'll thank yourself! -- and spring for one that truly works to the full extent. I use an off-brand Kenko that I purchased on eBay. Be be forewarned that not all Kenkos are fully functional, so be careful! Nikon, Canon and other's make their own sets. Of course, they are more expensive, but the advantage is that you know precisely what you're getting.

Just a bit of knowledge to be shared, especially with those who admire some of the macro work out there and want to jump into the pool in an inexpensive, but functional, way.