alternative real autostart for usb-sticks like U3 ?

..it's not possible to just copy it to a "normal" stick .
The reason it works IS that it's not a "normal" stick but a
"2 devices in 1" stick ..
But you might be able to load your own stuff on to the CD-ROM device
if there is software to do so available for your hardware .

See this site for instructions and some nice tools :
http://usb.smithtech.us/index.php

A minor clarification: I don't think you can do it on a garden-variety USB flash drive. A U3 drive (and, apparently, the fritz! drive) have special software that can make a portion of the USB flash drive look like a CD-ROM to the computer; the computer does its autorun thing to the fake CD-ROM. Since it usually handles autorun on CD-Roms differently than autorun on a USB drive, the autorun can work better that way. SmithTech's technique makes the U3 drive's fake CD-ROM drive boot up to software you might prefer instead of the default U3 software. So you end up tricking a tricky CD-Rom functionality.

For this to work, the machine must auto-run any CD-ROM that is inserted. This can be a security risk (how do you know someone isn't going to put a malicious CD-ROM into the drive?), so some people or companies turn off the auto-run functionality for CD-ROMs.

Sometimes we can get too tricky for ourselves.