It's easy to create a bootable USB thumb drive that can be used to install Windows 7.  All you need is a 4GB or larger USB thumb drive, a free tool from the <a href="http://store.microsoft.com">Microsoft Store</a> and a copy of the Windows 7 .iso file.  The tool works with both the retail and corporate versions of Windows 7.  This can be a great time-saver if you work in a corporate IT shop and have many Windows 7 desktops to install.

Installing Windows 7 from a thumb drive is faster than installing from DVD, and comes in really handy if the machine you are installing to doesn't have a DVD drive.

One other thing - make sure you are using a high-quality USB thumb drive. I couldn't get the tool to work with an inexpensive ($12) <a href="http://www3.pny.com/4GB-Micro-Swing-Attach---GREEN-P2833C428.aspx">PNY 4GB Micro Swing Attaché</a> drive, but it worked fine with a more expensive ($32) <a href="http://www.sandisk.com/products/usb-flash-drives/sandisk-cruzer-usb-flash-drive-(new-design!)">SanDisk Cruzer</a>.

The free tool can be downloaded from the Microsoft Store <a href="http://store.microsoft.com/Help/ISO-Tool">here</a> or from the CNET download site <a href="http://download.cnet.com/Windows-7-USB-DVD-Download-Tool/3000-18513_4-10972600.html">here</a>.  Some interesting history about why Microsoft recently open-sourced the code for this tool can be found <a href="http://arstechnica.com/microsoft/news/2009/12/microsoft-finally-open-sources-windows-7-tool.ars">here</a>.