English text seen in Japan. Engrish.com.

A transparent logo for fark.com, because http://userlogos.org/node/2759 isn't very high quality.

Logo for the news aggregation site, www.fark.com.

This is the logo for the bizarre humor site You're The Man Now Dog (YTMND) at 400x300. These images have a white outer glow, so they will work with any color background.

I was able to find a high enough resolution sample for this company's logo. I've included two additional thumbnail images: an abbreviated title and, well...you know who...as the website's mascot.

EDIT
Looks a whole lot better.
xkcd is "A webcomic of romance,
sarcasm, math, and language."

"Warning: this comic occasionally contains strong language (which may be unsuitable for children), unusual humor (which may be unsuitable for adults), and advanced mathematics (which may be unsuitable for liberal-arts majors)."

Having Trouble using transparent Logos? Click
here for help!

xkcd - A webcomic of romance, sarcasm, math, and language - By Randall Munroe, white logo with reflection. Updated: Added Transparent logos

xkcd - A webcomic of romance, sarcasm, math and language.
Ingenious humor by Randall Munroe.