Rewitness the legendary punch (in HD!).

Made using the source filmmaker (plus some additional assistance from Hammer).

EDIT: Now with subtitles! Courtesy of    • Video  .

EDIT 2: Somebody requested a wallpaper of the moment of impact. Here it is:
http://imgur.com/jjnrB

EDIT 3: Changed the subtitles.

EDIT 4: Tutorial for speeding lights:    • SFM Tutorial #01: Speeding light effect