I\'ve gotta agree with Mikey here, 3DO was good hardware for its time.. just too expensive and with little support.
In the case of N-Gage, the hardware is a step up from GBA.. but it has too many other flaws to beat out Nintendo\'s handheld. IMO, the GBA-SP won\'t face a challenge until the PSP is available. That is the only true test.
N-Gage compromises ease of play for more features, and is lacking in library. Hell, half of its games are probably going to GBA anyway; Super Monkey Ball is already out, for instance.