Ever been looking at a company's Web site (or printed brochure or product box) and wondered "How can that company afford these pricey models and professional photography?" Hey—we've been fooled too. Most likely, particularly with smaller companies, what you're actually looking at is stock photography.

A stock photo is one that hasn't been taken for a particular assignment or, after it's been used for editorial or commercial purposes, has been offered for resale. While you'll find stock photos for sale by individual photographers all over the Internet, the first place you'll likely stop for your photos is a stock photography service of some sort. Which type of service you use, however, depends on your needs and your budget.

At the low end of the scale are subscription-based image collections--such services offer access to all of their images for a membership or a regular fee. For instance, you might gain access to the site for one day, seven days, or a month, with the understanding that you have relatively unfettered usage rights (aside from reselling the photo) to the images you download in that period of time. Photos.com gives you such access for $99 a month, enabling you to download and use images in either 72 dpi (for Web and multimedia work) or 300 dpi files (good for printing). Photospin.com offers a one-year, $149 subscription for low-to-medium resolution images; Webspice.com ranges from $19.95 a month to $99 for the year. Clipart.com offers rates such as $7.95 a week for access to their photos (along with fonts, clipart and other items you might find handy for your site). The quality of the images may not be stellar or terribly original, but there's a chance you'll find a photo that's OK for your needs.

Subscription-based photo services can be a great bargain if you stumble on the right image or you need lots of images for little money; but what if you're simply not finding the perfect image for your site or materials? The next step up is to order royalty-free images a la carte. For that you'll find plenty of options, from Photostogo.com to Weststock.com to Imagesource.com to Superstock.com. You'll find that prices vary greatly, ranging (generally) from $29 to hundreds of dollars per image. Photodisc.com, for instance, offers Getty images at three different color-coded levels; if you want to limit yourself to images that cost about $29 for Web-based use, you can, or you can browse through images that cost hundreds for print use.

With royalty-free images, you can use the image repeatedly, although there are sometimes restrictions regarding whether the image can be used both for editorial and advertising, Web vs. print production and so on. One great place to start is Fotosearch.com, where you can search for photos offered by over 50 different stock-photo and stock-illustration houses. Once you find the photo you need, you can purchase it directly on the site or you can click over directly to a site that looks promising and search there. Prices on Fotosearch.com reflect the pricing set by the photography house that owns the artwork.

So what's beyond stock photography? At the high-end, you can buy specific publication rights to photos that give you exclusive use of the photo in certain markets or arenas or for a particular length of time. Generally you'll buy a "rights-managed" photo for a serious reason--you want to use it for a unique advertising or branding campaign or for a important editorial piece. For instance, Getty Images (www.gettyimages.com) offers rights-managed photos from Time-Life, National Geographic and in many different categories. Other services include Comstock.com, Corbis.com and Veer.com.

How much? Prices are based on the purpose of the image license, the length of time you want to use it, the reason for using it, whether you want exclusive use of it in a certain part of the world--and many other factors that add up quickly. Let's put it this way: You get what you pay for.