Getting FUSE to work...

My Linode is a Gentoo box. Which means tons of Portage, tons of Kernel source, etc. I would like to install FUSE, and use a Compressed FUSE FS Mount to store Portage and the Kernel Sources. I chose Gentoo because I wanted all my binaries as small and optomized as possible for my 'Node (I'm doing streaming audio and a bit of transcoding, so it needs to be streamlined)… but I'm not concerned about Portage "performance." If it takes a bit longer to emerge a program, that's a price I'll happily pay for Portage taking half it's normal space on the disk (leaving more room for audio).

But, when I try to emerge sys-fs/fuse, I get:

 * Could not find a usable .config in the kernel source directory.
 * Please ensure that /usr/src/linux points to a configured set of Linux sources.
 * If you are using KBUILD_OUTPUT, please set the environment var so that
 * it points to the necessary object directory so that it might find .config.
 *
 * ERROR: sys-fs/fuse-2.7.4 failed.
 * Call stack:
 *               ebuild.sh, line   49:  Called pkg_setup
 *       fuse-2.7.4.ebuild, line   29:  Called linux-mod_pkg_setup
 *        linux-mod.eclass, line  579:  Called linux-info_pkg_setup
 *       linux-info.eclass, line  846:  Called check_extra_config
 *       linux-info.eclass, line  698:  Called linux_chkconfig_present 'FUSE_FS'
 *       linux-info.eclass, line  277:  Called require_configured_kernel
 *       linux-info.eclass, line  264:  Called die
 * The specific snippet of code:
 *              die "Kernel not configured; no .config found in ${KV_OUT_DIR}"
 *  The die message:
 *   Kernel not configured; no .config found in /usr/src/linux
 *
 * If you need support, post the topmost build error, and the call stack if relevant.
 * A complete build log is located at '/var/tmp/portage/sys-fs/fuse-2.7.4/temp/build.log'.
 * The ebuild environment file is located at '/var/tmp/portage/sys-fs/fuse-2.7.4/temp/die.env'.

I remember having this problem before, wayback when I was running a Linode in the past. I'm using the stock Kernel with the stock Gentoo image from Linode, but apparently a .config isn't provided with the image, and therefore trying to get fuse installed won't work.

I might be missing a step, this is the first time I've tried to get FUSE to work on Gentoo.

(Also note: Gentoo helpfully installed gentoo-sources for the kernel source; I think there's a xen specific kernel sources available, but didn't want to interrupt Gentoo while it was doing it's thing. Do I need to do anything here?)