PromptHere v. 2.2 Added .ini file option UseGlass. May be set to 0 to disable blur behind glass effect on Vista/Windows Seven. Set it to 1 (the default) to enable.
edit: btw, the download includes ahk source to MilesAhead.ahk, which has misc. functions including _EnableBlurBehind() and _GlassEnabled() used by the app, and PromptHere.ahk. Also there's a Readme file and the program icon.