Hunter_Killers :
FRAPS really won't be going anywhere, its the only way to get near lossless recordings for video editing. Honestly if size is that big of an issue you probably shouldn't be attempting video editing without getting more storage or work at a lower resolution. It also doesn't take very long to encode what you've recorded to save space.
Anything thats smaller than what FRAPS is outputting at the same resolution/framerate will probably have heavy compression thats going to mangle your performance even more.
There's one good alternative to FRAPS, Dxtory. Not many know about this software though, since it's a Japanese software.
It allows different codecs to be used (in my opinion its default codec is better though, which has 4 quality settings available, True Quality, High Quality, Medium Quality, Low Quality), it allows recording to be done in any framerate, allows any resolution to be recorded (it can record at 100%, 75%, 50% or even a custom resolution), ...
I haven't tried FRAPS for a long time, so I don't know how Dxtory compares with FRAPS now. When I tried FRAPS the last time (I think it was version 3.03), FRAPS affected the framerate of the game while recording, but with Dxtory, recording doesn't affect/barely affects the framerate of the game, since there's an option for the recording FPS and the game FPS to not be synched.
Dxtory creates bigger files than FRAPS while recording though, so it's not a good software for those worried about FRAPS creating big files, since these are even bigger. :>
There is one really big bottleneck though, hard drive speed. For example, to record at my screen resolution (1440x900) I have to use the medium quality codec setting and record at 30fps.