The great thing about that new 6- or 8-megapixel camera you just picked up over holidays is its unparallel image sharpness and the ability to make poster-size prints. But honestly, how often do you get calls from concert promoters asking to turn your latest photos into promotional posters? It's a lot more likely that you'll want to share somewhat smaller versions of your photos.
The pitfalls of full size
Don't get me wrong; there's nothing wrong with taking pictures with your camera set to its maximum resolution, and then simply sharing those images with friends and family. I do that pretty often. But there's a downside. If you try to stuff a few 2MB images in an e-mail message, for instance, you might find yourself drumming your fingers waiting for it to upload, and although most e-mail services allow up to 10MB for attachments these days, you don't know the attachment limitations of all your recipients.
Your recipient might also not want such a large file. A friend of mine complains frequently about how big images are from modern digital cameras. Since he never prints enlargements, he just wants enough resolution to look good on his computer screen, and nothing more.
Finally, you might not want to give away the full-size image. Sharing smaller files means that only you can make large prints, which is a way to keep control over your photos.
Resizing the manual way
Virtually all image editors allow you to resize your image. Open a picture in Corel Paint Shop Pro, for example, and choose Image, Resize from the menu. Here, you'll find that there are several ways to resize: You can alter the image by pixel size, percentage of the original, or based on print size.
I'll assume that you'll usually want to resize to a specific pixel size. Make sure the menu is set to Pixels and then type in the size you're interested in. Make sure the "Lock aspect ratio" option at the bottom of the dialog box is checked. That'll keep the image's proportions correct as you enter a number in either width or height, like this.
Sometimes you might want to resize a photo for a specific print size. Suppose Uncle Bob tells you that he'd like to make a 5-by-7-inch print of one of your photos. In that case, ignore the Pixel Dimension section of the Resize dialog box and instead set the Print Size section to about 5 by 7 inches. Of course, unless your photo started out at an aspect ratio that was exactly 5 by 7, this resize won't be exactly 5 by 7 either. No matter -- just use common sense and choose a size that's approximately the right dimensions. Set the resolution to somewhere between 200 and 300 pixels per inch and you'll see something like this, then click OK and select File, Save As to make a copy for Uncle Bob.
Use the Image Resizer PowerToy
If you don't want to open a photo editing program just to resize a few images, you're in luck. Download the Image Resizer (ImageResizer.exe) from Microsoft's PowerToys site.
It's free, and it adds a convenient resize command to the context menu when you right-click on a photo icon. To install it, download the file to a convenient location, double-click on it, and follow the installation wizard prompts. Once it's installed, just select one or more photos, right-click, and choose Resize Pictures. You can select from a list of common image sizes or type in custom dimensions, then make a smaller copy; you can also select Advanced and resize the original. If you do a lot of resizing -- especially for Web sites or e-mail -- this is probably an essential add-on for Windows.
Resize for Outlook e-mail
Even without adding any new programs to your computer, there's a simple resizing tool built into Windows that you can use in conjunction with Outlook. Select one or more photos, then right-click, choose Send To, and select Mail Recipient. You'll see the Send Pictures via E-mail window, which lets you shrink the picture attachments before they're added to your Outlook e-mail message. To choose from several sizes, click the "Show more options" link at the bottom of the dialog box.
Resize for the Web
The Web is a great place to share photos, but I'm leery of posting the original full-size versions of my images. If I did this, anyone on the planet would has unfettered access to them. And I just don't like the idea of the president of Finland downloading pictures of my cat.
The solution? Resize your photos before you upload. This is easy to do at most online photo sharing services. I use Flickr, and I love the Flickr's handy Uploadr tool, which you can download from the service. You need to be a Flikr member to download and use the tool, by the way.
To resize your images on the fly, before you start using Uploadr, click the Settings button and specify that you want to resize all photos as they're uploaded. I stick with the option to always resize the longest side to 800 pixels, which is perfectly adequate for viewing on screen.