I love Japanese over-design. As an industrial designer, are you not awed by their willingness to fire up a whole new tooling line to create some product to tackle even the most minute, mundane problem? Case in point: Check out Mitsubishi subsidiary Uni's Promark View highlighter, which pushes the tip out to the end of a clear piece of plastic, so you can see precisely where you're highlighting. The only visual obstruction is the thin straw feeding the water-based ink out to the felt.
The Promark's chunky body will take up an undue amount of space in your pencil jar or pocket, but perhaps it's not designed to be stored in either: As this Japanese pen reviewer has noted, the wide, flat cap means it can stand up on your desk.
Back in its home country, the Promark View runs a reasonable ¥150; here in the U.S. online retailers are offering them for as low as $2.40 a pop. Comes in five colors.