How do I place a bootable ISO on a USB drive?
Is there a built in Windows 7 feature to "burn" an ISO to a USB-Stick USB-hard-drive?
Or are there any advisable tools for this task?
There is a tool here that can take the .ISO image, and put it on a USB drive.
Basically, once you download the utility from Microsoft, you follow the instructions to find the .ISO file, and the put it on the USB drive.
More information can be found on the link above.
Edit: My apologies, I totally misread your question. If you aren't burning a Windows 7 image, some other options are ISO to USB, or UNetBootin for Linux images.