I want to install CentOS 6.2 on a laptop (Thinkpad R40) which comes without CD/DVD-drive but with USB 2.0 ports.

It seems that CentOS does not provide ready-to-use dd-able USB images for installation.

Thus my question: How to install CentOS via a USB device (e.g. a 16 GB USB flash drive)?

Regarding using different available iso-images as base: the laptop has net-access - but I want to make sure that the CentOS installer is not loading unchecked packages from the net during installation - perhaps a netinstall image does not check cryptographically signed packages during installation ([as with the Fedora 14 installer](https://unix.stackexchange.com/questions/3817/are-packages-cryptographically-signed-in-fedora-14)).

There is a [CentOS InstallFromUSBkey](http://wiki.centos.org/HowTos/InstallFromUSBkey) which just provides outdated, cryptic and wrong information.

Especially, the instructions for CentOS 6 are missing details and contain errors (10 MB for the first partition is not enough, `syslinux device` fails and what are they talking about grub?)