Lightscreen, how do I love thee? Let me count the ways. Well, there are screen shots, window captures, area captures... Yes, I'm talking about my favorite screen grabber. It's the one I use to document my tire-kicking, capture Web pages, and of course, create the thumbnails and screenshots you see in my download reviews.
However, I've been a bit misleading as to the roots of my adoration. The real reason I love Lightscreen (free/donationware) is that it saves captures automatically to any folder I choose using the base file name I want, e.g., "Lightscreen", plus either a number or the time and date stamp. This feature has reduced my organizational chores immensely. The program also saves files in the increasingly popular png format, as well as jpeg, or bitmap. Additionally, the "Go to folder" command opens a window showing the folder containing my most recent screenshots--super handy.
My only gripe about Lightscreen is that you can't use Window capture on a dialog; you must use the area grab. Compared to the average user, I spend a lot of time capturing screens, and parts thereof. Lightscreen beats the tar out of Print Screen (which it will take over for if you wish) and Paint. It's unobtrusive and functionally darn near perfect, so it wouldn't hurt anyone to put it in their startup sequence. There's a portable version available as well.
If you do screen grabs more than once in a blue moon, Lightscreen is a must. I'll never love any software program purely, or with my childhood's faith, but I come darn close with this one.