I know most of you don't care for this sort of thing, but i'm really surprised it was never posted. It took me by complete surprise in the manga, so I hunted it down in cartoon form. Sorry about the quality...
It's during a fight with a villianous character called Buggy the Clown, who has the power to split his body into various pieces. However, unlike the rest of his body, his feet aren't capable of floating; therefore they're vunerable during his attacks, which Luffy takes full advantage of...
I know a certain anime Otaku (with Sephiroth as his avatar) who will shoot down my above description. XD
It's during a fight with a villianous character called Buggy the Clown, who has the power to split his body into various pieces. However, unlike the rest of his body, his feet aren't capable of floating; therefore they're vunerable during his attacks, which Luffy takes full advantage of...
I know a certain anime Otaku (with Sephiroth as his avatar) who will shoot down my above description. XD