Yeah, thanks for pointing out the requirement of GMP. I've recompiled xbindkeys to use the latest GMP. Get it and all its dependencies at:
http://kumatux.org/Applications.html
Instructions to install at:
http://sumoudou.org/%E7%9B%B8%E6%92%...ia%20N900.html
As I was at it, I've also compiled the latest Guile, so install all the latest versions, since I've rebuilt xbindkeys to use it.

Spits a segfault for me.

I cleaned out all the symlinks for kumatux. Re-installed everything with new versions, still dies out.

Here's a quick gdb dump;

Program received signal SIGSEGV, Segmentation fault.
0x400c9028 in vm_debug_engine () from /home/user/kumatux.org-root/2/3/libguile-2.0.so.18
0x400c9028 <vm_debug_engine+12>: str r0, [sp, #56]
Current language: auto; currently asm

That's very strange.

However, on a clean N900 rootfs, factory state, installing kumatux.org and linking:

xbindkeys_1.8.3_jj_2010-05-02-172000_fremantle_armel.tar.xz
gc_7.2alpha4_jj_2010-02-15-144600_fremantle_armel.tar.xz
gmp_5.0.1_jj_2010-03-25-074222_fremantle_armel.tar.xz
guile_1.9.10_jj_2010-05-02-123612_fremantle_armel.tar.xz
libunistring_0.9.2.1_jj_2010-02-15-121212_fremantle_armel.tar.xz

It runs fine, I just tested. On a clean N900 setup it starts and runs no prob. So it has to be something about your setup, your rootfs must be messed up somehow, this happens quite often if you install stuff from the sdk or devel repos.

That's why I developed kumatux.org, so you would never have to mess with the rootfs if you didn't want to and it would be clean at all times.

I have a lot of custom symlinks, however nothing that points or pulls any of the packages that kumatux.org is installing or has dependencies for.

On an clean n900, I installed all kumatux.org applications into ~/kumapps and got a segmentation fault when I ran guile.

When I linked /media/0/kumatux.org-apps/ to ~/kumapps/guile.... everything went fine.

Full Screen Toggle does not get any easier than this post

I even complied and included a working xbindkeys.