If you know Counter Strike: Source, once in cs_office I was the only survivor of the Terrorists team, at spawn, outnumbered by 4 counter terrorists.
The room as filled with smoke, and counter terrorists started invading looking for me.
I somehow managed to knife 3 of them, and ALMOST got the last one.
Unfortunately, I wasn’t recording the whole thing at the time, so I guess it’s something that’ll only be part of my own fuzzy warm memories…
And it was the single greatest thing I ever did, almost crapped my pants laughing and all, never heard of anything like it… ’till I watched this:

As you probably saw on Modern Warfare 2 trailers, you have the ability to throw knives (very important for the single player campaign – if you’re done with it you’ll know what I mean).
But this video is just insane! Guy’s just walkign around avoiding enemies and stuff then suddenly, comes a flying knife out of nowhere! xD

Source: Kotaku