I don't know what you mean by "cheaper", I didn't see any prices anywhere on the page referenced by the OP... And I don't know about "smaller" either, that's a pretty small device... But my brother just bought the phidgets.com USB accelerometer, to use as part of a racing package he's trying to build... It turns out that there's no software out there currently that can use a GPS and accelerometer to log your racing performance...

EDIT: An engineering acquaintance of mine suggested buying an accelerometer from sparkfun.com, but that requires some assembly (it appears that once again I'm an idiot )