This is the full-colour version of the currently unofficial Linux logo
("currently unofficial" just means that there has been no paperwork and
that I haven't really announced it yet). It was created by Larry Ewing,
and is freely usable as long as you acknowledge Larry as the original
artist.
Note that there are black-and-white versions of this available that
scale down to smaller sizes and are better for letterheads or whatever
you want to use it for: for the full range of logos take a look at
Larry's web-page: http://www.isc.tamu.edu/~lewing/linux/