Hi Phillip,
Although it is possible to set this attribute for this folder, I advise that you do not change the settings from their default - the same applies for all system folders. Your user folders are different - here you can set this attribute, but be aware that the amount of compression you achieve (and the disk space you gain) will depend on the type and size of files in the folder - you are unlikely to gain by compressing .MP3 and .JPG files (as they are already compressed), but will gain from the compression of text-based files. However, there is a downside to this. To access the files so that you can work with them, they need to be decompressed. Although the compression and decompression of files happens automatically, it can slow your system down and, depending on the hardware in your system and the size of the folders and files in question, it can be noticeable. Also note that if the routine that handles the compression and decompression becomes corrupted, then you could potentially lose the data.
Personally, I don't use this feature as this was more suitable to ealier OSes that were more limited in their hard drive capacity limits (back then, it was known as 'DriveSpace', or similar). Vista and modern motherboards can access much larger hard drives and I would go for the option of increasing capacity rather than compression.