I use MSI Afterburner for over/underclocking my cards, but it also has a handy screenshot feature which allows you to select image format etc, it is also great for taking movies as well, not to mention mapping framerates onto a handy graph. /advert.
"Tiger got to hunt, bird got to fly; Man got to sit and wonder, 'Why, why, why?' Tiger got to sleep, bird got to land; Man got to tell himself he understand." - A calypso.
i5 2500K@4.5Ghz | MSI P67A-GD53 | 8G DDR3 Corsair@1600 | Gainward GLH 460x2 SLI oc | Seagate Barracuda 1TB HDD | Antec Truepower New 750W PSU | Win 7 64bit | Black Widow HOTAS | Freetrack 2.2/PS3 eyetoy