There are two Keystroke launchers that i think are the best…and both are free:

1. Launchy: http://www.launchy.net/

*Here are some tips that we (Launchy Team) use and recommend.

• Search Google
  • Type in google, then tab, then your search query and press enter
• Check the Weather
  • Type in Weather, then tab, then your zip code or city,state and press enter
• Search other sites
  • Other sites you can search include wikipedia, msn, yahoo, amazon, netflix, imdb, and more.
• Browse your computer
  • Type in c:, then tab, then a folder or file, hit tab, and continue
• The Launchy Calculator
  • Did you know that Launchy has a built in calculator? Type in some algebra and see what happens!
• Index your Bookmarks & Folders
  • Directory: C:Documents and SettingsuserFavorites
  • File Type: .url
• Index your Music
  • Directory: My Documents
  • File Types: .mp3 .aac .ogg
• Index your Pictures
  • Directory: My Documents
  • File Types: .jpg .gif .bmp
• Index your Documents
  • Directory: My Documents
  • File Types: .doc .pdf .xls .ppt
• Index custom Commands
  • Directory: Your Custom Folder
  • File Types: .exe .bat .lnk

Launchy in action:

2. Enso Launcher: http://humanized.com/enso/launcher/

*these are just some of Enso's Commands:

• open – opens a typed program
• open with – opens a selected file with typed program
• learn as open – creates a new command
• unlearn – forgets a created command
• go – cycles through open programs
• minimize – minimize the active window
• maximize – maximize the active window
• unmaximize – unmaximize the active window
• close – closes the active program (not a typed program)
• quit – quits the active program (not a typed program)

All in all both are good but you can check them out in more details at their own site….i like them both but you can choose which ones you prefer…..