http://www.ogre3d.org/wiki/index.php/Faking_HDR
The graphics effects themselves looks pretty good, even the "very dumbed-down version" they used as an example. And I kindof doubt their dumbed-down version uses a tremendous amount of CPU power, either. (Even if it did, such Faking HDR could be an optional feature to be turned on or off in the options menu...)If you're in my situation... with a overall good graphics card but just lacking floating-point target support (what makes HDR), and you want to both achieve and be able to see HDR-ish effects, then you must get creative.