I'd like to put some image files in a Google Earth KMZ, but it makes
the actual KMZ file too large to download compared to others (1 MB
compared to 50KB), so I'd like to store these images in a online
location that I could reference to from within my KMZ for direct
download by the person viewing my file. Where can I have files hosted
for free that are available for direct linking and downloading, with
no limits on bandwidth? (within reason; we're not talking about GBs
per month here)

For an idea of what it is I'm talking about, check out the following
file (my pride and joy :) )

http://www.googleearthhacks.com/dlfile6643/Mexico-City-Metro-System.htm