If you rotate the favicon of HugeURL by 90 degrees to the left,you'll get the favicon of Foo Hack. Were they made by the same person?
The glider emblem was made famous by ESR: http://www.catb.org/~esr/hacker-emblem/
A lot of sites use the glider as their favicon.
The glider is an "animal" from conway's game of life and has been popularized as a "hacker" symbol for a while, though I don't think it ever caught on in a huge way.