chris@ubuntu:~$ vmware
vmware is installed, but it has not been (correctly) configured
for this system. To (re-)configure it, invoke the following command:
/usr/bin/vmware-config.pl.

chris@ubuntu:~$ sudo /usr/bin/vmware-config.pl 
Making sure services for VMware Server are stopped.

Stopping VMware services:
   Virtual machine monitor                                             done
   Bridged networking on /dev/vmnet0                                   done
   DHCP server on /dev/vmnet1                                          done
   Host-only networking on /dev/vmnet1                                 done
   DHCP server on /dev/vmnet8                                          done
   NAT service on /dev/vmnet8                                          done
   Host-only networking on /dev/vmnet8                                 done
   Virtual ethernet                                                    done

Configuring fallback GTK+ 2.4 libraries.

In which directory do you want to install the mime type icons? 
[/usr/share/icons] 

What directory contains your desktop menu entry files? These files have a 
.desktop file extension. [/usr/share/applications] 

In which directory do you want to install the application's icon? 
[/usr/share/pixmaps] 

/usr/share/applications/vmware-server.desktop: warning: The 'Application' category is not defined by the desktop entry specification.  Please use one of "AudioVideo", "Audio", "Video", "Development", "Education", "Game", "Graphics", "Network", "Office", "Settings", "System", "Utility" instead
/usr/share/applications/vmware-console-uri-handler.desktop: warning: The 'Application' category is not defined by the desktop entry specification.  Please use one of "AudioVideo", "Audio", "Video", "Development", "Education", "Game", "Graphics", "Network", "Office", "Settings", "System", "Utility" instead
Trying to find a suitable vmmon module for your running kernel.

None of the pre-built vmmon modules for VMware Server is suitable for your 
running kernel.  Do you want this program to try to build the vmmon module for 
your system (you need to have a C compiler installed on your system)? [yes] 

Using compiler "/usr/bin/gcc". Use environment variable CC to override.

What is the location of the directory of C header files that match your running
kernel? [/lib/modules/2.6.20-10-generic/build/include] 

Extracting the sources of the vmmon module.

Building the vmmon module.

Using 2.6.x kernel build system.
make: Entering directory `/tmp/vmware-config0/vmmon-only'
make -C /lib/modules/2.6.20-10-generic/build/include/.. SUBDIRS=$PWD SRCROOT=$PWD/. modules
make[1]: Entering directory `/usr/src/linux-headers-2.6.20-10-generic'
  CC [M]  /tmp/vmware-config0/vmmon-only/linux/driver.o
In file included from /tmp/vmware-config0/vmmon-only/linux/driver.c:80:
/tmp/vmware-config0/vmmon-only/./include/compat_kernel.h:21: error: expected declaration specifiers or ‘...’ before ‘compat_exit’
/tmp/vmware-config0/vmmon-only/./include/compat_kernel.h:21: error: expected declaration specifiers or ‘...’ before ‘exit_code’
/tmp/vmware-config0/vmmon-only/./include/compat_kernel.h:21: warning: type defaults to ‘int’ in declaration of ‘_syscall1’
make[2]: *** [/tmp/vmware-config0/vmmon-only/linux/driver.o] Error 1
make[1]: *** [_module_/tmp/vmware-config0/vmmon-only] Error 2
make[1]: Leaving directory `/usr/src/linux-headers-2.6.20-10-generic'
make: *** [vmmon.ko] Error 2
make: Leaving directory `/tmp/vmware-config0/vmmon-only'
Unable to build the vmmon module.

For more information on how to troubleshoot module-related problems, please 
visit our Web site at "http://www.vmware.com/download/modules/modules.html" and
"http://www.vmware.com/support/reference/linux/prebuilt_modules_linux.html".

Execution aborted.

chris@ubuntu:~$ which gcc
/usr/bin/gcc
chris@ubuntu:~$ gcc -v
Using built-in specs.
Target: i486-linux-gnu
Configured with: ../src/configure -v --enable-languages=c,c++,fortran,objc,obj-c++,treelang --prefix=/usr --enable-shared --with-system-zlib --libexecdir=/usr/lib --without-included-gettext --enable-threads=posix --enable-nls --program-suffix=-4.1 --enable-__cxa_atexit --enable-clocale=gnu --enable-libstdcxx-debug --enable-mpfr --enable-checking=release i486-linux-gnu
Thread model: posix
gcc version 4.1.2 (Ubuntu 4.1.2-0ubuntu4)
chris@ubuntu:~$ dpkg -l | grep header
ii  linux-headers-2.6.17-10                    2.6.17.1-10.34                         Header files related to Linux kernel version
ii  linux-headers-2.6.17-10-generic            2.6.17.1-10.34                         Linux kernel headers for version 2.6.17 on x
ii  linux-headers-2.6.17-11                    2.6.17.1-11.35                         Header files related to Linux kernel version
ii  linux-headers-2.6.17-11-generic            2.6.17.1-11.35                         Linux kernel headers for version 2.6.17 on x
ii  linux-headers-2.6.20-10                    2.6.20-10.17                           Header files related to Linux kernel version
ii  linux-headers-2.6.20-10-generic            2.6.20-10.17                           Linux kernel headers for version 2.6.20 on x
ii  linux-headers-generic                      2.6.20.10.6                            Generic Linux kernel headers
chris@ubuntu:~$ cat /etc/issue.net 
Ubuntu feisty

vmware-server-kernel-modules-2.6.20-15 - vmware-server modules for Linux (kernel 2.6.20)
vmware-server-kernel-modules - vmware-server kernel module dependency package