I've always enjoyed the way Google plays around with the masthead on their web page. By replacing one or more letters with an object that fills in for the letter, they keep things interesting.
When other corporations go for an effect like this, it doesn't always hit the mark. The bank I use, Scotiabank, is sponsoring the AIDS Walk For Life in September and has advertising all over town.
Someone had the idea to try and tie the red AIDS ribbon we're all familiar with into the bank's logo. I may be the only one who sees it this way but that second 'a' in their logo now looks more like an 'o' if you ask me.
All I see now is Scotiabonk AIDS Walk For Life! Oh my.