=== Sense ===
http://abulafia.hcoop.net/~aku/hcoop_logo/hcoop_sense.png

=== Clear ===
http://abulafia.hcoop.net/~aku/hcoop_logo/hcoop_clear.png

=== Fade ===
http://abulafia.hcoop.net/~aku/hcoop_logo/hcoop_fade.png

From the Attic:  http://abulafia.hcoop.net/~aku/hcoop_logo_attic.html

=== geek ===
http://abulafia.hcoop.net/~aku/hcoop_logo/hcoop_geek.png

=== Ztesch ===
http://fyodor.hcoop.net/~bpt/hcoop-small.png

=== Planet ===
http://detriment.org/planet-round.png

http://detriment.org/planet-round.svg

 Best logo yet!  I very much like the circled-planet center.  Not so sure I like the cropped "h" on top, perhaps it could be modified.  But this one is showing promise.
 How about changing it to a fat, capital H instead? Something like a less ugly/more stylized version of this:
  http://hcoop.net/~ntk/planet-round-mod.png
 (Obviously that H is too wimpy-looking, but that seems to be a more balanced-looking/symmetrical logo.)  --NathanKennedy