life can be so easy ...

phaidros@daddl:~/workspace/openrd/openrd.git$ sudo aptitude install uboot-mkimage
The following NEW packages will be installed:
  uboot-mkimage 
0 packages upgraded, 1 newly installed, 0 to remove and 5 not upgraded.
Need to get 9,876B of archives. After unpacking 57.3kB will be used.
Get:1 http://de.archive.ubuntu.com/ubuntu/ lucid/main uboot-mkimage 0.4build1 [9,876B]
Fetched 9,876B in 0s (61.7kB/s)      
Selecting previously deselected package uboot-mkimage.
(Reading database ... 52121 files and directories currently installed.)
Unpacking uboot-mkimage (from .../uboot-mkimage_0.4build1_i386.deb) ...
Setting up uboot-mkimage (0.4build1) ...

phaidros@daddl:~/workspace/openrd/openrd.git$ make ARCH=arm CROSS_COMPILE=/home/phaidros/workspace/openrd/arm-2010q1/bin/arm-none-linux-gnueabi- uImage
  CHK     include/linux/version.h
  CHK     include/generated/utsrelease.h
make[1]: `include/generated/mach-types.h' is up to date.
  CALL    scripts/checksyscalls.sh
  CHK     include/generated/compile.h
  Kernel: arch/arm/boot/Image is ready
  SHIPPED arch/arm/boot/compressed/lib1funcs.S
  AS      arch/arm/boot/compressed/lib1funcs.o
  LD      arch/arm/boot/compressed/vmlinux
  OBJCOPY arch/arm/boot/zImage
  Kernel: arch/arm/boot/zImage is ready
  UIMAGE  arch/arm/boot/uImage
Image Name:   Linux-2.6.33-rc8-00099-gb4cb3f9
Created:      Wed Aug 25 17:42:47 2010
Image Type:   ARM Linux Kernel Image (uncompressed)
Data Size:    2561572 Bytes = 2501.54 kB = 2.44 MB
Load Address: 0x00008000
Entry Point:  0x00008000
  Image arch/arm/boot/uImage is ready

yippieh, not longer complaining about missing mkimage .. thanks ubuntu (though possibly it came directly from Debian, so thanks to you uys as well !!! )