_________________About Dr. Horrible's Sing-Along Blog
Written by Joss Whedon, Zack Whedon, Jed Whedon, & Maurissa Tancharoen during the 2007–2008 Writers Guild of America strike. Their idea was to create something small for not a lot of money and to release it exclusively on the Internet. The musical was filmed in Los Angeles, California and released July 2008 in three acts on Dr. Horrible.com.

The musical is about an aspiring supervillain named Dr. Horrible. His dream is to be included in the Evil League of Evil & he is in love with a girl named Penny. Captain Hammer is his nemesis and happens to make Penny his girlfriend after saving her. Dr. Horrible vlog's his journey as he attempts to defeat Captain Hammer and please Bad Horse.

Dr. Horrible/Billy Buddy is played by Neil Patrick Harris.
Penny is played by Felicia Day.
Captain Hammer is played by Nathan Fillion.

_________________Screencaps
You can find screencaps for Dr. Horrible at my screencap gallery - Royal Caps.