I was getting tight for space on my 8G SSD. Some SYSTEM folders had become very large, and I knew of no way to move them to another storage device. I have a 16G SD card which has many of the larger programs and suites installed on it. Came across the JUNCTION command:
http://technet.microsoft.com/en-us/sysinternals/bb896768.aspx
Which allowed me to move the entire c:Windows/Installer to my SD card (D: drive). This function causes Windows to believe that it is referencing a folder on the C: drive which has been moved to some other device.
This capability may be useful to anyone trying to conserve space on C:.
Download and unzip the function. Stuff it in the Windows/SYSTEM32 folder and follow the examples at the above web site. There are also a number of functions in the SYSINTERNALS SUITE referenced in the Utilities section at this site.