check out the buildroot, build the default version:

svn co http://svn.gumstix.com/gumstix-buildroot/trunk \
                                  gumstix-buildroot
cd gumstix-buildroot
make defconfig  # maybe make arch=ARM defconfig
make menuconfig # maybe make arch=ARM menuconfig

configure the gumstix/buildroot according to your needs.

make             # maybe make arch=ARM

Edit the kernel's config to include inotify. It's in "build_arm_nofpu/linux-2.6.xy/.config". Look for "#CONFIG_INOTIFY is not set" and edit it to say "CONFIG_INOTIFY=y"

remove previously built kernel images to force a rebuild:

rm rootfs.arm_nofpu.jffs2
rm build_arm_nofpu/root/boot/uImage
rm build_arm_nofpu/linux-2.6.15gum/arch/arm/boot/uImage
rm build_arm_nofpu/linux-2.6.15gum/arch/arm/boot/zImage
rm build_arm_nofpu/linux-2.6.15gum/arch/arm/boot/compressed/vmlinux
rm build_arm_nofpu/linux-2.6.15gum/linux.bin

rebuild the kernel:

make arch=ARM