It`s not working witch my oem.tgz which I am using for ESXi4.1! Need I a new one oem.tgz for ESXi5.0 ?

Yes, new drivers are needed. Please read the docs I posted.

- Andreas

Is it possible to create an bootable USB stick with your ESXi-Customizer?

You can use LinuxLive USB Creator to create a bootable USB stick.

This will only create a bootable USB stick from the iso file, it cannot be used to customize the iso with drivers, this has to be done in some other way.
If you just need the original iso to be on a bootable usb stick, this works fine.
http://www.linuxliveusb.com/

I prefer a solution without a linux os. In the past i make it witk vmware player, ubuntu 10, linuxscript. But i like it simple. A Windows tools/script that make all in
one step would be my favorit choice.

And i need additonal drivers in my usb boot stick.

No. Unfortunately, with ESXi 5.0 this is not as easy as it was with ESXi 4.x, because there is no dd-image anymore that you just need to write to a USB-stick.

http://www.linuxliveusb.com/ is a windows tool/program. It just takes an iso file and puts it on a bootable USB stick.
Once you have an ESXI v5 iso file with you customized drivers, you can use it to create the bootable usb.

So basicaly you could use the ESXI customizer to create the iso with the drivers you want, and then use linuxlive USB to create the bootable usb stick.
Two steps is not that much

Two steps are more than one Step And i hope that a new release of the Customizer will do the job in one step.

What I did was to install vmware player and booted up the installation ISO on it and installed it on a USB stick

Do you try this program?

This program make a bootable Stick with from the install iso of ESXi. You can boot from this stick an then install ESXi somewhere.

But i want a ESXi5 installed ON a USB Stick.

For ESXi4 there are scripts that do this and i put my ESXi4 with additional drivers with these scripts. But the don´t support Version 5 now.