I'd just like to draw your attention to an add-on for Xillinux, which easily allows switching to a kernel with nearly all configuration options enabled, including some that seem quite useless, and still.
The add-on consists of a kernel binary and lots of kernel modules. No kernel compilation is needed.
Other precompiled kernels I've seen around so far (Xillinux' original kernel included) have been configured for a minimal settings, and it turns out that there's a demand for all kinds of USB devices, file systems, networking capabilities etc.
This "enriched" kernel will go along with the next version of Xillinux. Until then, comments are welcome (below), in particular if something is still missing, if some configuration could have been done better, or if bad things happen with this kernel binary.
Download this add-on: http://xillybus.com/xillinux-rich-kernel
Xillinux' main page: http://xillybus.com/xillinux