@font-face LESS Mixin

demo.less

// USE
.font-face(Ubuntu-Regular, 'https://dl.dropbox.com/u/1220078/ubuntu-new/Ubuntu-Regular-webfont', 400, normal);
.font-face(Ubuntu-Italic, 'https://dl.dropbox.com/u/1220078/ubuntu-new/Ubuntu-Regular-Italic-webfont', 400, italic);
.font-face(Ubuntu-Bold, 'https://dl.dropbox.com/u/1220078/ubuntu-new/Ubuntu-Bold-webfont', 700, normal);
.test {
  .font(Ubuntu-Regular, 1em, normal, normal);
  
  h1 {
    .font(Ubuntu-Bold, 1.7em, bold, normal);
  }
  i {
    .font(Ubuntu-Italic, inherit, normal, italic);
  }
  b {
    .font(Ubuntu-Bold, inherit, bold, normal);
  }
}

fontface-mixin.less

/**
 * @font-face LESS Mixin
 * use: .font-face(
 *   @font-family, // name
 *   @file-path,   // absolute/relative URL to font files
 *   @font-weight, // light/normal/bold/inherit | 300/400/700
 *   @font-style   // italic/normal/inherit
 * )
 */
.font-face(@font-family, @file-path, @font-weight, @font-style) {
  @font-face {
    font-family: @font-family;
    src: url('@{file-path}.eot');
    src: url('@{file-path}.eot?#iefix') format('embedded-opentype'),
      url('@{file-path}.woff') format('woff'),
      url('@{file-path}.ttf') format('truetype'),
      url('@{file-path}.svg#@{file-path}') format('svg');
    font-weight: @font-weight;
    font-style: @font-style;
  }
}

/**
 * font LESS Mixin
 * use: .font(
 *   @font-family, // name
 *   @file-size,   // any unit/inherit
 *   @font-weight, // light/normal/bold/inherit | 300/400/700
 *   @font-style   // italic/normal/inherit
 * )
 */
.font(@font-family, @font-size, @font-weight, @font-style){
  font-family: @font-family;
  font-size: @font-size;
  font-weight: @font-weight;
  font-style: @font-style;
}